A Critique of Evolutionary Psychology
Kirk Honda, Psy.D., LMFT
October 7, 2014
Charles Darwin foresaw evolutionary psychology when he wrote “In the distant future... Psychology will be based on a new foundation, that of the necessary acquirement of each mental power and capacity by gradation” (1859, p. 449). Darwin was correct in his prediction in that evolutionary theory has had a significant impact on psychology, being applied to such diverse topics as anorexia (Fehr, Hendricks, Abed, & Figueredo, 2005), body building (Jonason, 2007), sexual jealousy (Harris, 2003), flirting (Frisby, Dillow, Gaughan, & Nordlund, 2011), filicide (Friedman, Cavney, & Resnick, 2012), and many other topics in psychology. However, Darwin did not foresee the controversy and conflict surrounding these ideas that would rage well into the 21st century.
This article provides a brief look into these controversies and a summary of the history and concepts of biological evolutionary theory and evolutionary psychology. Recent research, on a variety of topics within evolutionary psychology, will be detailed and critiqued.
Author’s note: I tend to get three responses to this document: 1) appreciation and thanks, 2) harsh criticism for acknowledging the potential usefulness of evolutionary psychology, or 3) harsh criticism for questioning conclusions within evolutionary psychology. Before writing this, I was not aware of the apparent polarization within our field. If you, the reader, would like to critique my critique, please provide specific assertions rather than general comments. Statements such as “you have no idea what you’re talking about” are not helpful to me. In contrast to these hurtful statements, I would rather have an open and respectful dialogue with readers. Since I am not an evolutionary psychologist, I expect there are problems with my arguments. I do not claim to be an expert on the topic. The following is merely the humble result of 5 weeks of casual reading and is not meant to be the definitive document on the subject. Having said that, I hope you find this useful and I invite you to email me at firstname.lastname@example.org
A general critique I have of evolutionary psychology literature is the frequent omission of clear definitions. As a remedy to this lack of clarity, I will attempt to use clear, well-defined terms throughout this article.
The word evolution has many definitions ranging from narrow to broad. For example, some writers use the term evolution to refer solely to genetic evolution while others use it to refer to cultural changes via memes and learning. Other authors use the term evolution to refer to the complex human process of genetics and culture coevolving over time. And others define evolution as any process of change, in any domain. For the sake of clarity, in this article, evolution and evolutionary psychology will refer to biological and genetic changes and not evolved cultural changes. This delimitation in the definition is not intended to diminish the importance of culture and learning, rather, it is intended to draw a clearer distinction between two important variables.
Throughout ancient history, most people believed human beings had been created directly by God or by some other supernatural phenomenon. For example, according to the Bible, the first human beings, Adam and Eve, sprang into existence by God’s will (Gen. 1:26 New International Version). Cultures around the globe often have such stories of creation.
Due, in part, to cultural changes in Europe during the Enlightenment, some thinkers began looking for empirical evidence of our genesis. In the late 1700s, Erasmus Darwin, Charles Darwin’s grandfather, introduced the idea that all living things emerged from a common ancestor. He also hypothesized that competition was the driving force behind evolution. Later, in 1859, Charles Darwin proposed a plausible mechanism for this evolutionary change in his book On the Origin of Species. Thus began the study of evolution by natural selection.
Around the same time, Gregor Mendel, an Augustinian monk, discovered the genetic inheritance of traits through his experimentation on pea plants. Although Mendel’s laws of inheritance were rejected at first, later in the early 1900s, it was rediscovered and coupled with Darwin’s theory of natural selection – this coupling was called neo-Darwinian or modern evolutionary synthesis. Later, advances in science led to discoveries in genetics (e.g., the discovery of DNA) which added to our understanding. Darwin’s theory provided a process while genetic science provided a mechanism. Both process and mechanism were incorporated into biological evolutionary theory. Evolutionary theory has since become the most powerful explanatory system in the life sciences.
Biological Evolution: Major Concepts
The theory of natural selection is based on three basic premises: variation, inheritance and adaptation. The premise of variation refers to the idea and observation that all individuals of a particular species show variation in their behavioral and physiological traits. In other words, no two instances of a species are physically or behaviorally identical (Barrett, Dunbar & Lycett, 2002; Hampton, 2010; Workman & Reader, 2004). The composite of an individual’s particular traits are referred to as its phenotype. The inheritance premise is based on the observation that these variations in phenotype are inherited from one’s parents, and some of that variation will be passed on from one generation to the next (Barrett, Dunbar & Lycett, 2002; Hampton, 2010; Workman & Reader, 2004).
The premise of adaptation refers to the competition among individuals for scarce resources such as food, mates, and shelter, and some of these phenotypes allow some individuals to compete more effectively than others (Barrett, Dunbar & Lycett, 2002; Hampton, 2010; Kolber & Crothers, 2003; Workman & Reader, 2004). Those individuals who are better able to garner resources are more likely to produce offspring, and the resulting offspring are likely to inherit those beneficial traits. This is the process of natural selection, or the selection of genetic traits that increase the individual organism’s chance of producing offspring. Through this ongoing process, organisms become adapted to their environment. These advantageous traits are described as “naturally selected” because the organisms that are more “fit” for the environment are able to survive and pass on a greater proportion of their genetic material to the next generation. This process is called biological evolution.
As a metaphor for biological evolution, imagine you have a cake recipe. People like your cakes, so they come to your house and hand copy the recipe. Occasionally there are copy errors (or mutations) in the recipe. Most of these mutations result in substandard cakes – for example, a cake made with sawdust instead of flour. Each time a repulsive cake is produced, that mutated recipe is thrown away, while the exact copies are propagated through the neighborhood and into other neighborhoods. At any one time, there are a small percentage of mutated recipes in the community that have yet to be selected out of the pool of recipes. One day, someone accidentally changes the recipe for the better – it has the addition of chocolate chips. Everyone starts asking for this new mutated recipe. Over time, the original recipe diminishes in number and eventually becomes extinct altogether since it cannot compete with the new recipe. And the cycle continues. Each preferred mutation is selected for, creating better and better cakes. Now imagine there was a sudden change in the environment: chocolate chips became scarce. Remember that at any one time, there are mutated recipes being created due to copy errors. One of these mutated recipes is perfectly suited for this chocolate chip famine: a cake with yogurt chips instead, which are abundant. Even though yogurt chips are not as tasty as chocolate chips, this yogurt chip trait is propagated through the neighborhood since it is adaptive to the current environment.
In the natural world, as in the metaphor above, genetic copying errors usually lead to either no effect or a reduction in survivability, resulting in these traits being potentially selected out of the gene pool. But on very rare occasions, a mutation might produce an organism that is better fitted to the environment and therefore better able to reproduce. As with the yogurt chip cookie recipe, an organism that is better fitted to the environment will slowly edge out the competition.
It should be noted that there is a difference between a genetic mutation (any change in a DNA sequence away from normal) and a polymorphism (a DNA sequence variation that is common in the population). Scientists have arbitrarily defined the cut-off point between a mutation and a polymorphism as 1 per cent – if the frequency of a trait is lower than 1 per cent, it is considered a mutation. For example, among all humans, hair color varies from blond to black (polymorphism), but occasionally someone is born with no hair (mutation). Both polymorphisms and mutations may propagate through the gene pool by natural selection as organisms evolve (Barrett, Dunbar & Lycett, 2002; Hampton, 2010; Workman & Reader, 2004).
According to evolutionary biology, all living organisms on earth, including humans, are descended from a single common ancestor 4 billion years ago. About 3.5 billion years ago, the first cells evolved, and around 600 million years ago, the first multicellular organisms appeared in the sea. 500 million years ago, the first land organisms evolved – first microbes and then plants. Then some of the sea-dwelling animals evolved to live on the land – first insects, then amphibians, reptiles, dinosaurs, birds and mammals. Around 55 million years ago, the first primates evolved. They were small agile tree-dwellers akin to modern lemurs. From this species of primate evolved all modern primates: monkeys, apes and humans. The first modern humans (homo sapiens) appear in the fossil record around 150,000 years ago in Africa. And according to the current paleoanthropological consensus, about 100,000 years ago, some of these humans left the African continent and began to populate the rest of the world (Barrett, Dunbar & Lycett, 2002; Evans & Zarate, 2000; Hampton, 2010; Workman & Reader, 2004).
Darwin himself wrote of evolutionary psychology in that he suggested that like any other trait, human mental faculties are the outcome of evolution by natural and sexual selection and suggested these mental faculties should be understood in light of common descent (as cited in Bolhuis, Brown, Richardson & Laland, 2011). Since Darwin, many have studied and written within the broad field of evolutionary psychology – that is, the evolutionary-oriented study of human behavior and cognition. A number of distinct camps have emerged including evolutionary psychology, behavioral ecology, ethology, sociobiology, behavioral genetics, evolutionary developmental psychology, biocultural evolution, evolutionary anthropology, Darwinian anthropology, evolutionary neuroscience, and others. There is considerable overlap, and also disagreement, between these schools of thought. Some authors (including this author) call for a unified approach with less antagonism (Barrett, Dunbar & Lycett, 2002). However, divisions and controversies remain between and within each camp.
This article is concerned with one of those camps: evolutionary psychology. However, it should be noted that the term “evolutionary psychology” is sometimes used as a narrow school of thought while others use it as an umbrella term for all camps that utilize Darwinian ideas to understand and explain human thought and behavior (Hampton, 2010). Also, some consider evolutionary psychology to be rebranding of sociobiology and other previous camps (Hampton, 2010).
In the effort of clarity, throughout this article, I will attempt to delineate between what I term as “mainstream” evolutionary psychology and the broader whole of evolutionary psychology. I provided the label “mainstream” since some within the field of evolutionary psychology disagree with the theoretical proposals put forward by the Santa Barbara camp and other prominent figures in the field (Bolhuis, Brown, Richardson & Laland, 2011).
The History of Evolutionary Psychology
Over the millennia, there has been much debate regarding human instincts (Hampton, 2010). Perhaps in reaction to this heated debate, Darwin altogether avoided the topic of instincts. However, later, William James, one of the most influential figures in early psychology, proposed in the late 1800s that humans have even more instincts than other animals (Workman & Reader, 2004). He outlined instincts such as fear, love and curiosity as driving forces of human behavior. And later in the early 1900s, William McDougall famously proposed that the human mind has certain innate or inherited tendencies which motivate all thought and action and that these instincts are probably common to all humans (Hampton, 2010). He defined an instinct as an inherited and innate psycho-physical disposition which determines what someone pays attention to, what someone will feel upon perceiving it, and what someone will do upon that feeling.
This instinct theory has been supported by the observation that other organisms come into the world with innate knowledge and abilities. For example, a recently hatched turtle instinctually crawls to the sea and swims, a puppy instinctually knows how to suckle without being taught, and a foal can walk within minutes after birth. While most people may find it easy to believe that animals have instinctual behaviors, some find it difficult to acknowledge the possibility that humans have instincts as well (Workman & Reader, 2004). Why would all other animals have instincts while humans would have none? Perhaps it is discomforting to think of our behavior as being dictated by fate and out of our direct control. Perhaps we like to think of ourselves as beyond nature.
Consider the following question: Why do apes suckle their babies? Is it due to instinct? Now consider a second question: Why do human mothers breast feed their infants? Does the mother breast feed because she loves her child and has learned that the infant needs nourishment? Or is it instinctual? Does the ape mother breast feed her baby because she “loves” her child? Or is the ape merely motivated by instinct? Is love a tool to motivate instinctual behaviors? These are difficult questions to answer. However, people tend to view animal behavior as instinctual and human behavior as conscious and thoughtful (Barrett, Dunbar & Lycett, 2002). Perhaps both apes and humans have a mixture of both instinct and reason. Perhaps reason is a product of instinct. Do we have free will? How much does learning and culture play a role in our behavior? Or are we merely slaves to biological impulse? This confusion has not deterred many within several disciplines from attempting to understand our innate human instincts.
Ethology. The notion of instincts was taken up by naturalists and zoologists in Europe in the 1930s who studied animal behavior with an interest in humans as a particularly interesting member of the animal kingdom (Hampton, 2010). These scientists were interested in innate, inherited, instinctual behavior rather than learned behavior. Ethology has contributed much to our understanding of evolutionary psychology including the concepts of imprinting and critical periods.
Sociobiology. The term “sociobiology” emerged in the 1940s and was made famous by E.O. Wilson and Richard Dawkins in the 1970s. This discipline analyzes the social behavior of species from a biological and genetic point of view (Hampton, 2010). Sociobiology has been concerned with various topics such as altruism and parental investment. The core idea of sociobiology is that behavior, in parallel with biology, has evolved under natural and sexual selection.
It should be noted that sociobiologists have been heavily criticized by scientists, philosophers and activists for providing an evolutionary justification for oppression and the status quo (Brinkman, 2011; Workman & Reader, 2004). For example, starting in the 1980s, E.O. Wilson was criticized for his claims that humans have evolved instincts to make war and for intimating that women have evolved as specialized egg makers (Workman & Reader, 2004).
Human Behavioral Ecology. In the 1960s, human behavioral ecology, a branch of anthropology, emerged as the study of human behavior in its natural and spontaneous contexts (Hampton, 2010). It assumes that human behavior is adaptive and organized around a wider unconscious strategy to optimize survival and reproduction. In this way, it studies the evolution of adaptive advantages of individual, group, and cultural traits.
The Emergence of Evolutionary Psychology. Contemporary evolutionary psychology was taken up in the 1980s by a school of thought stemming from the University of California at Santa Barbara (Barrett, Dunbar & Lycett, 2002; Bolhuis, Brown, Richardson & Laland, 2011). As a hybrid between cognitive science and evolutionary biology, the main purpose of evolutionary psychology is to apply the knowledge and principles of evolutionary biology to develop research that leads to a better understanding of human experience and behavior (Blasi & Causey, 2010; Buss, 2009).
According to Hampton (2010), evolutionary psychology built upon understandings within instinct theory – the emphasis on psychological dispositions. It also adopted the ethological study of how organisms operate in the here and now and why they have come to exhibit the behaviors that they do. Like sociobiology, evolutionary psychologists views behavioral adaptations as linked to genetic adaptations. And like human behavioral ecology, evolutionary psychology is interested in using depictions of our natural history to test hypotheses. However, unlike sociobiologists and other related disciplines, evolutionary psychologists attempt to explain human behavior in terms of cognitive psychology or the underlying computations that occur within the mind (Workman & Reader, 2004).
Mainstream Evolutionary Psychology: Main Concepts
The essence of the mainstream, Santa Barbara brand of evolutionary psychology is summarized in the following famous and pithy statement: Our modern skulls house a Stone Age mind (Barrett, Dunbar & Lycett, 2002; Bolhuis, Brown, Richardson & Laland, 2011). According to this school of evolutionary psychology, human minds are organized into a large number of evolved psychological mechanisms which are psychological adaptations designed to solve recurrent problems faced by our hunter-gatherer ancestors (Bolhuis, Brown, Richardson & Laland, 2011). Evolutionary psychologists seek to discover and clarify these evolved psychological mechanisms by reverse-engineering the mind from an observable phenomenon to its proposed adaptive function (Bolhuis, Brown, Richardson & Laland, 2011).
In the 1980s, the Santa Barbara school influenced the establishment of the following four widespread major tenets of evolutionary psychology (Bolhuis, Brown, Richardson & Laland, 2011): massive modularity, universal human nature, the environment of evolutionary adaptedness, and gradualism.
Massive Modularity. As with cognitive psychologists, evolutionary psychologists propose that the mind consists of cognitive modules (Bolhuis, Brown, Richardson & Laland, 2011; Friedman, Cavney & Resnick, 2012). They believe that much, if not all, of our behavior can be explained by internal psychological mechanisms. Different sets of adaptive problems require different computational solutions. This model argues that these cognitive modules have each evolved through natural selection in response to stimuli that result in advantageous behavior. These psychological mechanisms are information-processing models that are designed by natural selection to attend to certain components of the environment (Hastings & Shaffer, 2008). Each mechanism pays attention to particular environmental cues and reacts according to its evolved function. For example, we evolved a psychological mechanism to reward us with pleasurable neuronal processes when we orgasm. This is designed to motivate us to have sex and reproduce.
As a recent elaboration on this concept, Bernard, Mills, Swenson, and Walsh (as cited in Bernard, 2008) developed a theory that proposed a model of human behavior using 15 independent neuropsychological adaptations – or motive constructs – that propel behavior. These motivation constructs evolved from natural, sexual, and social selection pressures in the ancestral human environments in the African Pleistocene savanna and continue to mediate behavior today. The 15 motives are Affection, Aggression, Altruism, Appearance, Conscience, Curiosity, Health, Legacy, Material, Meaning, Mental, Physical, Play, Safety, and Sex.
Universal Human Nature. Evolutionary psychologists believe there are universal elements of human nature comprising a species-specific repertoire of evolved psychological mechanisms (e.g., a childhood fear of strangers or a preference for specific mate characteristics) (Bolhuis, Brown, Richardson & Laland, 2011). Evolutionary psychology posits that universal forms of behavior exist – along with their underlying genetic counterparts – because they have provided some competitive advantage and were therefore selected.
The Environment of Evolutionary Adaptedness. This term refers to the environment in which a species has evolved and to which it has become adapted through natural selection (MacLennan, 2007). Specifically regarding humans, this concept refers to the notion that our psychological mechanisms have evolved in response to our ancestral environments in the African Pleistocene savanna (Bolhuis, Brown, Richardson & Laland, 2011). In other words, our ancestors thrived on the African savanna, and, as a result, certain psychological traits that aided in survival in that environment were selected and are still seen in modern humans (Fitzgerald & Danner, 2012). Since our species spent over 99.5% of its history as hunter-gatherers living in small kinship groups a few dozen in size in Pleistocene environments (about 2,500,000 to 12,000 years ago), our evolved psychological mechanisms were adapted to that environment and not to the industrialized world of today (MacLennan, 2007). Thus, evolutionary psychology attempts to make predictions about human psychological mechanisms by considering those psychological traits that would have perhaps been adaptive in the African Pleistocene environment (Horne, 2004; Kolber & Crothers, 2003).
Gradualism. Evolutionary psychologists argue that psychological mechanisms do not evolve quickly. Since human environmental factors have recently changed rapidly, these ancestral psychological mechanisms may produce maladaptive behaviors in response to this mismatched environment (Bolhuis, Brown, Richardson & Laland, 2011).
Current Evolutionary Psychology
According to Brinkman (2011), evolutionary psychology is one of the fastest growing fields in psychology. To some, it is applicable to almost any aspect of human behavior. And it enjoys a wide popularity in the media due to its often appealingly simple explanations for seemingly odd human tendencies. Similarly, according to Kruger and Armenti (2012), scholars in various fields – not only evolutionary psychology – are increasingly adopting evolutionary theory as the foundation of understanding in the human sciences, yet there is a perception that evolutionary theory yields little or no practical implications for the human sciences. Furthermore, since many authors have proposed highly controversial and unsupported claims, evolutionary psychology has a justifiably tainted reputation. As it stands today, evolutionary psychology is an enormous field with much internal and external controversy (Brinkmann, 2011).
Upon a review of the literature, I found hundreds of studies on various topics. In an attempt to categorize all research within evolutionary psychology, Buss (2009) identified the following major domains: survival, sexuality, mating strategies, sexual conflict, parenting, kinship, cooperation, aggression. Webster, Jonason, and Orozco (2009) also offered a different list of categories: altruism, kin, gender differences, sex, attractiveness, mate selection, and general human behavior. However, I found several studies outside these proposed categories. More and more research is being published every year. And a search of literature published in recent months produced as many critiques as studies.
For this article, I attempted to find and include research that represented the common elements I found to exist in most of the studies within the field of evolutionary psychology. I also attempted to include research that showcased the usefulness of evolutionary psychology.
How do we evaluate evolutionary psychology theories? How do we know if the conclusions of the research are sound? We should remain skeptical of claims since much of the provided evidence within evolutionary psychology is speculative even though the authors rarely admit it. For instance, evolutionary psychology is based on the highly speculative notion that we can infer the environment of our ancient African ancestors. For some authors, it might be tempting to invent stories about our origins to justify some pre-determined conclusion. As with any field, authors within evolutionary psychology have been influence by political and sociocultural factors. For example, researchers have been known to propose that men are naturally more aggressive, and, by implication, are therefore excused from aggressive behavior (e.g., E.O. Wilson). More examples of this will be given later.
Twins studies. Workman and Reader (2004) and Hampton identify the following five methods used by evolutionary psychologists to evaluate their theories. First, evolutionary psychologists study separated twins to delineate the effects of genes and the environment. As a simple example, a researcher might survey a group of twins, separated at birth, to determine if aggression was genetically determined or determined by the environment – if twins separated at birth tended to show similar rates of aggression, that suggests aggression is at least partially determined by genetics. Twins studies can provide good evidence of instincts. However, the limitations should always be discussed upon using twins study data. For example, if identical twin boys are separated at birth, but remain within the same culture, it is difficult to determine which traits were genetic and which were learned.
Animal research. Second, evolutionary psychologists compare humans to other animals such as apes. This method of theory evaluation assumes that 1) the innate instincts of other primates may be similar to the innate instincts of humans, 2) ape instincts are easily determined through observation, and 3) the ape behavior under observation is not learned through culture. When evolutionary psychologists cite animal research as evidence of their claims, they should disclose the limitations to these assumptions, of which there are several. However, authors rarely do so.
Cross-cultural research. Third, research in evolutionary psychology seeks cross-cultural evidence to demonstrate universality and therefore innateness. If a particular psychological trait is innate then we might expect to find it in all cultures (e.g., laughing behavior). This method of theory evaluation has limitations such as the possibility that several ancestral cultures independently adopted similar cultural elements (e.g., misogyny).
Computer models. Fourth, evolutionary psychologists use mathematical and computational modeling which gives researchers the opportunity to tinker with variables to determine possible adaptations in our past. Those within mainstream evolutionary psychology consider the brain to be a computer—a physical system that was designed to process information (Cosmides & Tooby, 2001; Tooby & Cosmides, 2005). If this assumption is accepted, software can be designed to model the mind and its psychological mechanisms, and environmental elements can be varied to test hypotheses regarding how those psychological mechanisms might have evolved in humans. This method assumes that the researchers can accurately model the human mind and its environment.
Modern hunter-gatherers. Fifth, by studying present-day hunter-gatherer societies as possible analogues of early humans, evolutionary psychologists attempt to evaluate their hypotheses. This evaluative method assumes that modern-day hunter-gatherers are sufficiently similar to humans on the African Pleistocene savanna. It also assumes that all modern hunter-gatherer societies are homogenous.
Even though these five methods may provide fruitful conclusions, responsible researchers should understand and clearly disclose the underlying assumptions as questionable and potentially speculative. However, in my literature review, I rarely saw such discussions. It could be speculated that evolutionary psychology authors are afraid of revealing research limitations for fear of losing credibility. However, due to a lack of such disclosures, many within the scientific community seem to be distancing themselves from evolutionary psychology for fear of being associated with bad science. On the other hand, evolutionary psychology’s denial of limitations may have been a major factor in the general public becoming more and more convinced by their conclusions, making them some of the most popular authors of our time (e.g., Pinker, Buss, Dawkins). All of this should be kept in mind as we consider the following research.
Fehr, Hendricks, Abed, and Figueredo (2005) examined the causal relationship between the evolved psychological mechanism of female intrasexual competition and eating disorders. They surveyed 202 undergraduate women attending the University of Arizona. The study examined the following three tenants of an evolutionary psychology theory of eating disorders first outlined by Wasser and Barash in 1983 (as cited in Fehr, Hendricks, Abed, & Figueredo, 2005): 1) anorexia represents an adaptive attempt at reproductive suppression by the affected female – this is based on the observation that females in other animal species appear to suppress reproduction when environmental conditions are unfavorable; 2) anorexia is a manifestation of reproductive suppression of subordinates by dominant females within a process of female intrasexual competition; and 3) anorexia and bulimia stem from the process of female intrasexual competition (a.k.a., the sexual competition hypothesis). The authors explain that the sexual competition hypothesis is based on the Darwinian theory of sexual selection. More specifically, they explain that human females have innate motivations to display cues of physical attractiveness involving signs of youth and good health to attract male mates.
Fehr, Hendricks, Abed, and Figueredo (2005) argue that rising female intrasexual competition in our current American culture has led to an increase in the prevalence of eating disorders, and that this change in culture is due to: 1) declining fertility which leads to prolongation of women’s youthful appearance, 2) increasing instability of long-term relationships that has led to females repeatedly return to the mate market, 3) increasing prevalence of media images of youthful females, and 4) living in large cities with numerous other youthful-looking autonomous females.
Fehr, Hendricks, Abed, and Figueredo (2005) claim their findings lend support to the contention that eating disorders originate from female intrasexual competition for mates. After analyzing their results, the authors found their model supports the hypothesis that eating disorders may have originated from the human female’s innate psychological adaptation to be concerned with physical attractiveness in order to attract and retain a mate. The authors argue their findings support the assertion that female intrasexual competition for mates drives two major pathways in their model of causality: 1) female intrasexual competition for mates positively influences both body dissatisfaction and drive for thinness, which in turn contributes to both anorexia and bulimia; and 2) high female intrasexual competition for mates also positively influences high female intrasexual competition for status, general competitiveness, and perfectionism, which in turn contributes to anorexia but not bulimia. In other words, due to recent changes in U.S. society which frustrate female intrasexual competition, the authors argue that the female instinctual urge to compete with other females for mating males has caused some females to stop eating as an innate competitive strategy.
Critique. According to Barrett, Dunbar and Lycett (2002), “human behavior and psychology are the products of evolution and can be investigated profitably using an evolutionary framework, although any approach that ignores the fact that culture is an integral part of the biological process will, of necessity, be incomplete” (p. 21). Even though the researchers considered the influence of culture upon the instinct, the possibility of culture entirely supplanting instinct was not considered. It seems possible that a culture that idolizes thin women and socializes women to base their self-esteem upon their attractiveness might be the culprit and not the proposed instinctual urge to compete with other women. It is extremely difficult to determine whether or not this behavior is innate or learned.
This is an all too common critique of evolutionary psychology. Brinkman (2011) astutely points out that, often in evolutionary psychology, the individual is considered to be independent of social and cultural factors. Due, in part, to contemporary capitalistic politics, evolutionary psychology has downplayed and denied the importance of culture. This synthesis with capitalism and individualism is perhaps why evolutionary psychology has been so popular in recent times. The ignorance of culture within evolutionary psychology is exemplified by the following quote from Ingram, Campos, Hondrou, Vasalou, Martinho and Joison (2012):
Our results support the theory that male and female humans exhibit different patterns of interpersonal conflict, some aspects of which are relatively culturally invariant (at least within Europe), and may therefore be biologically motivated. Boys were much more likely to talk about conflicts occasioned by competitive sports or games, whereas girls talked more about conflicts that centered on whether someone else was defined as a friend and whether they were fulfilling the obligations of friendship correctly. (p. 893)
The argument that European children represent all humankind is not only spurious but it is also racist and offensive.
Another critique of the Fehr, Hendricks, Abed, and Figueredo (2005) study is a common critique of all psychological research in general. Since this study only examined American university students, there is a significant threat to external validity. This limitation can be blamed on economics. Due to budget constraints, university students are usually recruited for underfunded psychological studies.
The authors’ model proposes causal links that are perhaps problematic. They argue that human females unconsciously attempt to compete with other females for male mates by starving themselves. This could be considered a Kipling ‘just-so’ story (Workman & Reader, 2004) – or an unverifiable and unfalsifiable narrative explanation – since the researchers do not provide, in my opinion, compelling ‘hard’ evidence for their argument. Along these lines, it is unclear what evolutionary psychology might add to existing sociological theories since its arguments appear to be untestable, as it is difficult to evaluate the truth of claims that refer to events happening in the far distant past (Horne, 2004).
According to evolutionary biology and evolutionary psychology, humans evolved to survive in the African Pleistocene savanna. However, today’s environment is very different from that ancestral environment. This mismatch between our evolved psychological traits and today’s environment is detrimental to our well-being (Fitzgerald & Danner, 2012). Consider the following examples of how our current environment is mismatched with our evolved psychological mechanisms.
Food cravings. Foods that were high in protein and fat were needed for survival but not easily obtained on the savanna. Therefore, the craving for these foods was positively selected. Today, technology has made these foods cheap and easily available, but our evolved craving has remained constant, resulting in our modern obesity epidemic (Fitzgerald & Danner, 2012). This phenomenon is known as the mismatch hypothesis (Eaton et al., as cited in Fitzgerald & Danner, 2012).
Biophilia and the workplace. According to Fitzgerald and Danner (2012), the human trait of biophilia is an appreciation and longing for our natural environment. This trait may have been positively selected as a benefit to survival on the African Pleistocene savanna. Evidence of this is shown in workplace research which has shown that implementing natural elements in the workplace, such as sunlight and greenery, can exude specific psychological benefits in the workplace (Fitzgerald & Danner, 2012). The authors also identify research finding that employees strongly desire offices with windows because sunlight increases feelings of relaxation, job satisfaction, and well-being, and lowers intentions to quit. Furthermore, Fitzgerald and Danner identify an abundance of research finding links between urban living and a variety of psychological ills. For example, when urbanites increased their contact with nature, they experienced increases in concentration, attention, cognitive functioning, and prosocial behaviors, as well as decreases in blood pressure, stress, anxiety, and depression. This suggests the urban environment somehow clashes with our evolved biophilia which results in increased fear, stress, and psychopathology.
Critique. The mismatch hypothesis is based upon assumptions regarding our ancestor’s environment, how we interacted with it, and how we evolved as a result. There are many assumptions and guesses based upon few direct observational data. Plus, it is difficult to determine whether workers prefer nature as a result of innateness or culture or both. However, in regards to the food cravings research discussed above, it seems highly probable we, in our ancient past, evolved a taste for food that was rare and beneficial – although culture and learning most likely also play a role in the food we crave.
Another critique of the workplace research can be summed up by the pithy saying “correlation does not equal causation.” For example, the observation that sunlight is associated with higher job satisfaction could be the result of a number of possible phenomena. For example, due to culture, people might associate offices with windows as having more prestige, and more prestige increases job satisfaction. Cultural causation was not considered by the authors. Instead, they assumed the data was evidence of the biological evolution of the human brain. This is not to say their assumptions are incorrect, but rather, their assumptions were not sufficiently supported.
Parents Murdering Children (Filicide)
In applying evolutionary theory to the study of filicide, Friedman, Cavney and Resnick (2012) explored the hypothesis that killing one’s own children has served as an adaptive reproductive strategy for early humans and this psychological impulse has survived as part of the human behavioral repertoire. They identify the following key points regarding child murder by parents: 1) most child homicides are perpetrated by their parents – half by mothers and half by fathers; 2) the highest risk of child homicide is on the first day of life and these early-acting perpetrators are most often mothers; 3) stepparents kill at much higher rates than biological parents; 4) motives from child murder include maltreatment, altruistic killing, acutely psychotic, unwanted child, and partner revenge; 5) 24 nations, including the U.K. and Australia, have decreased penalties for mothers who kill their child within the first year of life; 6) the U.S. rate of infanticide is 8 per 100,000 while the Canada rate is only 3 per 100,000; 7) despite public perception, a large percentage of child murders are committed by parents who are not seriously mentally ill.
Hrdy (as cited in Friedman, Cavney & Resnick, 2012) suggests that infanticide was an evolved reproductive strategy for early humans – if a newborn was defective or born at a time when the parents are having difficulty, the child would require unwanted cost and effort in child-rearing. As a real world example, of the mothers in India who are hospitalized for postpartum mental illness, 43% had thought about murdering their child and 36% had infanticidal behavior (Chandra, Venkatasubramamian, & Thomas, as cited in Friedman, Cavney & Resnick, 2012). Based on these and other observations, Friedman et al. believe mothers who suffer from postpartum depression and suicidality may murder their children as an altruistic act – to prevent the child from the suffering of being abandoned if the mother commits suicide.
The authors claim that “evolutionary psychology helps explain differences between evolutionarily normal rationales for filicide and mental abnormal filicides,” (p. 792) and “evolutionary psychology demonstrates that some filicides are rational acts, specifically by identifying contemporary parental motives that may have equivalence to the adaptive pressures of our evolutionary past” (p. 792). These quotes exemplify the authors’ attempt to provide mitigating evolutionary psychology legal arguments for individuals being tried for filicide. In this way, this article appears to be a ‘how-to’ for forensic psychologists who evaluate perpetrators of filicide and how to use evolutionary psychology to establish the defendant is not guilty by reason of insanity.
The conclusions provided by Friedman, Cavney and Resnick (2012) are not in isolation. Many prominent evolutionary psychologists and sociobiologists (e.g., Martin Daly & Margo Wilson) have provided similar arguments that the murder of children might be the result of an implicit cost-benefit analysis made by a parent (Workman & Reader, 2004).
Critique. My main critique of this article has to do with the potential moral good or moral bad of its use. If the knowledge from this article is used for good (e.g., helping a legitimately suffering young mother who murdered her child out of instinctual insanity – getting her psychiatric treatment rather than prison), then this article, and its questionable conclusions, is a good thing in my humble opinion. However, if this article is used to harm society (e.g., helping a sociopathic sadist to be found not guilty), then, I would say, this article is a bad thing.
Additionally, the authors’ choice of words raises questions. When Friedman, Cavney and Resnick (2012) claim that “evolutionary psychology helps explain differences between evolutionarily normal rationales for filicide and mental abnormal filicides,” (p. 792) are they claiming there are only two causes of filicides: 1) ‘evolutionarily normal’ and 2) ‘mental abnormal filicides’? The authors did not provide any answers to these questions.
Also, they provided some interesting statistics (e.g., step-parents are more likely to murder their step-children than biological parents) and then claimed that humans must have evolved an instinct to murder their children when resources were scarce and are therefore merely acting according to their programming. In my opinion, the authors did not provide evidence to support the claim that filicide is instinctual and out of the murderer’s control. This is not to say that filicide did not evolve as an adaptive psychological mechanism, rather, the authors did not provide compelling evidence of this claim.
When Friedman, Cavney and Resnick (2012) write “evolutionary psychology demonstrates that some filicides are rational acts, specifically by identifying contemporary parental motives that may have equivalence to the adaptive pressures of our evolutionary past,” (p. 792) they are making the argument that sane parents who murder their children may be merely acting upon an evolved instinct to rationally murder one’s child. According to this logic, almost any human behavior can be rationalized this way. For instance, it could be argued that by killing millions of innocent people, Hitler was merely acting upon his instinct to raise his status so he could gain more mates and thereby propagate his genes more successfully. Or perhaps he was merely enacting an innate strategy of reducing the population of an over-crowded world. Unless carefully considered and supported with overwhelming science, using evolutionary psychology to justify antisocial behavior is a flippantly dangerous and potentially immoral act.
Furthermore, the discussions presented in this article are reductionistic. The reasons and thought processes that precede the murder of one’s child are likely to be highly varied and complex. Therefore, to reduce this complex deviant behavior to a simple proposed instinct is problematic.
Flirting and Attraction
According to mainstream evolutionary psychology, all humans, regardless of culture, evolved universal psychological mechanisms in the form of interpersonal needs for the ultimate purpose of reproduction (Buss, as cited in Frisby, Dillow, Gaughan, & Nordlund, 2011). These evolved interpersonal needs take various forms depending on the social context. In response to the early stages of romantic and sexual encounters, we evolved instincts for flirting as a tactic that can be used to facilitate the satisfaction of our interpersonal needs (Frisby, Dillow, Gaughan, & Nordlund, 2011).
Parental investment. According to Parental Investment Theory, men are attracted to physical beauty and youth since these characteristics signal fertility and health which are essential features for women to produce offspring; women, on the other hand, are attracted to men’s resources and dominance since these are characteristics that signal men’s ability to protect the woman and her offspring (Frisby, Dillow, Gaughan, & Nordlund, 2011; Workman & Reader, 2004). Also according to Parental Investment Theory, women may sacrifice physical attractiveness in men to obtain paternal investment and are more selective than men when choosing a mate. Providing support for this assertion, research by McCormick and Jones (as cited in Frisby, Dillow, Gaughan, & Nordlund, 2011) found that women were more active than men in escalation and de-escalation of flirtation – in this way women are able to control who they allow and disallow to flirt with them. Also, Parental Investment Theory proposes that men attempt to attract women by focusing on demonstrating more dominance while women attempt to attract men by increasing their physical attractiveness.
Flirting is innate. In support of the claim that flirting is innate and universal, Frisby, Dillow, Gaughan, and Nordlund (2011) identify research that found that adolescent females flirted nonverbally in a manner similar to adult women and that gender differences in flirting are clearly established by age three. The authors claim these findings suggest that flirtatious behaviors may have both socialized and innate elements.
Procedure. To study the evolutionary basis of flirting, Frisby, Dillow, Gaughan, and Nordlund (2011) had 252 U.S. undergraduates view a flirtatious role-played interaction and rated the flirter’s physical and social attraction, affiliation, dominance, and conversational effectiveness. The participants were shown a still shot of the flirter (of the opposite sex) they would be rating and were asked to provide evaluations of the flirter’s physical attractiveness prior to watching the role-played interaction. Then the participants watched a 4-minute clip which depicted the flirter flirting with another individual. Role-playing flirters were instructed to flirt for a set of reasons: for sexual reasons, for exploration, for fun, and for relational reasons. After the viewing, participants completed measures of their perception of the flirter’s physical attraction, social attraction, affiliativeness, dominance, and conversational effectiveness.
Findings. The authors claim their findings support parental investment theory and other common evolutionary psychology understandings of flirting in the following ways: 1) men flirters were perceived by women respondents as more dominant when flirting for sexual reasons and more conversationally effective when flirting to explore; 2) women flirters were perceived by men respondents as more conversationally effective when flirting for fun and relational reasons; 3) both men and women flirters were perceived as affiliative when flirting; 4) women flirters who were perceived by men respondents as affiliative were also perceived as more physically attractive, socially attractive, and conversationally effective; 5) women flirters who flirted for sexual motivations were perceived by men respondents as more attractive than in the original evaluation of physical attraction – this is in line with the commonly held evolutionary psychology understanding that men face problems in identifying females who are sexually available, and “women flirting for sexual motivations may be perceived as available and reduce the time spent by males in acquiring sexual resources” (p. 691). In other words, when women flirt sexually, men perceive this as a cue that this female will require less effort to impregnate and the men therefore pursue her since, according to mainstream evolutionary psychology and parental investment theory, men try to impregnate as many women as possible for the least amount of effort.
However, contrary parental investment theory and other mainstream evolutionary psychology understandings of flirting, male dominant flirting was not related to women respondents’ ratings of the flirter’s physical attraction, social attraction, or conversational effectiveness. The authors propose the following explanation for this unexpected finding: “while it may be true women unconsciously choose dominant male partners because of survival of their offspring, they may not report that they actually prefer men who behave in a dominant fashion” (p. 691).
Critique. Frisby, Dillow, Gaughan, and Nordlund (2011) exhibit dubious logic. When their findings support commonly held evolutionary psychology understandings, they conclude the understandings must be a true representation of innate, universal instincts. However, when their findings contradict the common understandings, the authors conclude the respondents must have been hiding their true, unconscious motivations.
Frisby, Dillow, Gaughan, and Nordlund (2011) argue that gender-stereotypical flirting is innate since adolescent females were found to flirt nonverbally in a manner similar to adult women. This argument is spurious since it is possible that teen girls were socialized similarly as adult women. They also argue that gender-stereotypical flirting is innate since gender differences in flirting are clearly established by age three. This is also spurious since it is possible that young girls have been exposed to cultural expectations of gender. Along these lines, Berenbaum, Martin, and Ruble (2008) identify numerous studies demonstrating that culture indoctrinates children into gender-stereotypical behavior from an early age. For example, gender stereotypes about clothing, activities and games are known to children as early as age 2.5 (Martin et al., as cited in Berenbaum, Martin, & Ruble; 2008).
As with many studies in evolutionary psychology, this study only included heterosexual people. There was no mention of non-heterosexual people. It is my opinion that evolutionary psychology researchers choose to ignore this large population since queer individuals have motivations and behavior counter to many established evolutionary psychology theories. For example, if women supposedly evolved psychological mechanisms to appear young and thin to attract dominant men, then a gay woman who chooses to appear dominant and unattractive to men provides a major wrench in the gears of mainstream evolutionary psychology. The omission of queer populations in evolutionary psychology research provides major challenges to the study’s validity and could be seen as heterosexist.
In my opinion, the frequent argument within mainstream evolutionary psychology that men are programed to impregnate as many women as possible is sexist. For example, in the study discussed above, Frisby et al. (2011) found that women flirters who flirted for sexual motivations were perceived by men respondents as more attractive than in the original evaluation of physical attraction. This can be interpreted in a number of ways depending on one’s perspective of men. However, Frisby et al. (2011) consider only one interpretation: men are looking for easiest way to impregnate women. As an alternative explanation (that was not in the article), men are looking for attachment and companionship and they have learned that a sexual encounter sometimes results in a long-term, satisfactory relationship, and therefore, they are programed to respond to sexual flirting. There are many more plausible explanations.
However, I will give the authors credit for writing: “flirtatious behaviors and their underlying motives may have both socialized and innate elements” (p. 683). In my review of the evolutionary psychology literature, I rarely saw this admission. If authors in mainstream evolutionary psychology discussed this possibility of socialization and admit they are perhaps speculating about evolved psychological mechanisms, I would be more likely to respect their claims. Perhaps they choose to ignore culture because today’s society is more interested in easy-to-understand, biological explanations – but this is mere speculation.
Researchers in evolutionary psychology have studied the evolved psychological mechanisms involved in violent behaviors. According to mainstream evolutionary psychology, human biological evolutionary selection is indifferent to morals; therefore, evolution may produce both prosocial and antisocial adaptations for survival and reproduction (Goetz, 2010).
Violence is innate. Goetz (2010) provides the following evidence that violence is hard-wired and innate: 1) skeletal remains of ancient humans show direct evidence of violent, purposeful injuries inflicted by other humans; 2) modern-day hunter-gatherer societies are proposed to offer a glimpse at a life that would have been similar to that of our ancestors, and homicide rates in many of these societies are much greater than even the most violent American cities (e.g., Chagnon, as cited in Goetz, 2010); 3) the cross-cultural ubiquity of violence suggests humans have had a violent past; 4) chimpanzees and other mammals strategically use violence and aggression to negotiate their social world; 5) since upper-body strength is assumed to be crucial for men-on-men combat, men have evolved 90% greater upper-body strength than women.
Goetz (2010) discusses previous research documenting that the majority of homicides occur between unrelated men over threats to status – arguments escalate between young, unemployed, unmarried men in which an individual challenges or undermines the status of another. Mainstream evolutionary psychology proposes that the male psychological mechanism to become violent in response to threats of status was positively selected during our ancient past due to sexual selection. In other words, it is assumed that ancient women chose to have sex with men with high status thereby selecting the male genetic determinants of the motivation to fight someone who threatens one’s status.
Southpaws. Goetz (2010) also discusses a speculative hypothesis that humans have evolved to occasionally produce offspring with left-handedness as a man-on-man combat advantage. Handedness is highly heritable and left-handedness is associated with fitness costs (e.g., more vulnerable to immune system deficiencies) which is offset by the benefit associated with left-handedness during violent combat as evidenced by modern day southpaw’s advantage in sports such as boxing and fencing.
Mismatch. Since our African ancestors did not have modern weaponry such as guns, this psychological mechanism for violent dominance rarely resulted in homicide. However, since many Americans now own guns, some of these status threats result in homicide. Therefore, the prevalence of guns provides an environmental mismatch resulting in the maladaptive behavior of murder.
Study. Goetz (2010) also identifies experimental research testing hypotheses regarding the underlying evolved psychology of violence conducted by Griskevicius, Tybur, Gangestad, Perea, Shapiro and Kenrick (as cited by Goetz, 2010). This research found that men who had read a scenario involving status competition (i.e., competing for a promotion at work) were more likely to respond aggressively when another male spilled a drink on them. Additionally, male participants who read a scenario involving going on a date with a highly desirable woman were also more likely to respond aggressively when another male spilled a drink on them, but only when there were male observers present. According to mainstream evolutionary psychology, these findings suggest that we evolved psychological mechanisms for activating violent behavior in response to social competition for status and to specific environmental information, such as the sex of the audience.
Sexual jealousy and domestic violence. Goetz (2010) explains the mainstream evolutionary psychological perspective regarding jealousy as an evolved psychological mechanism. He discusses the hypothesis that ancestral women may have recurrently threatened their male partner’s fitness by having sex with other men which provided selective pressure that generated psychological mechanisms for spousal violence as a solution to cuckoldry. If a man’s wife had sex with another man and became impregnated with another man’s child, the husband might unknowingly invest time and energy into another man’s offspring instead of his own. To Goetz (2010), this proposed story of our ancestors makes it clear how selection could have favored the evolution of strategies and tactics (a.k.a., sexual jealousy) aimed at eliminating partner infidelity and decreasing paternity uncertainty.
Also according to mainstream evolutionary psychology, men and women both experience jealousy, but men evolved to experience sexual jealousy while women evolved to experience emotional jealousy (Buss, 2003). According to this theory, ancestral women needed to secure a man’s investment of time and resources to help raise offspring and this need exerted a selective pressure for women to be more distressed by a partner's emotional infidelity. However, since ancestral men could not guarantee paternity, men evolved psychological mechanisms to be more distressed by cues associated with a partner's sexual infidelity. This hypothesis has been supported by over three dozen empirical studies according to Goetz (2010). Since sexual jealousy is one of the most frequently cited causes of domestic violence (Daly et al., as cited in Goetz, 2010), Goetz hypothesizes that the evolved instinct to commit domestic violence originally functioned “to punish and deter female infidelity” (p. 18).
Sexual jealousy and murder. Occasionally, sexual jealousy results in the killing of the wife. Buss (2003) asserts that at first glance, murdering one’s wife must be an accidental over-use of the evolved behavior of domestic violence since it eliminates the man’s access to reproduction – which is the assumed primary motive for coupling. However, Buss (2003) points out the high number of men who intentionally kill their wife for reasons of sexual jealousy. He hypothesizes men evolved a specific psychological mechanism for killing one’s wife under extreme sexual jealousy because: 1) extreme abandonment by the wife will eliminate her as a reproductive partner regardless; 2) the wife may channel her reproductive resources to another man, thereby increasing his competitor’s reproductive success, and by extension, lowering his own; and 3) letting her live will incur the additional cost of damaging his reputation which will ultimately damage his chances with subsequent women.
Critique. The fact that archeology has found evidence that ancient humans were violent with each other does not prove we have an innate psychological mechanism for violence. Those ancient people had culture too – they could have developed a culture of violence just as we have today. Plus, we do not know the circumstances of that ancient violence. Perhaps ancient humans were mostly non-violent and only violent in times of desperation, such as a draught. This is not to say that ancient humans were not violent – it seems they likely were – but this is to say that it is difficult and problematic to assume ancient motivations and then use those assumptions as the basis for the theory of innateness.
Regarding sexual jealousy and murder, it is impossible to determine the underlying cause of the various murders of women by men. Is it innate? Or do we live in a paternalistic and sexist culture that socializes boys and men to believe they own their intimate partners? Or is it both? Or is it some other factor? These are difficult, if not impossible, questions to answer given our current scientific capabilities. Also, it is dangerous to attribute wife-murder to evolution since it might support paternalism and the status quo by justifying the aberrant behavior. Before any dangerous claim is made, researchers should be sure their science is sound.
Goetz (2010) provides the following critique: “Any honest discussion of human aggression must concede that evolution is responsible, but this concession does not suggest that all forms of human aggression are engendered by specialized evolved mechanisms that were directly selected for” (p. 16). Even within his responsible critique, he makes the assumptive statement that evolution is unquestioningly responsible for human aggression. In my opinion, evolutionary psychology has not provided enough evidence to make such a confident claim. Plus, human behavior is much too complex to make such a reductionistic claim.
According to Jonason (2007), mainstream evolutionary psychology researchers have found that, due to sexual selection, men have instincts to look larger, whereas women should be more likely to enact behaviors to look smaller. He cites literature claiming that due to sexual dimorphism, women prefer men with larger upper bodies and men prefer smaller women. He hypothesizes that the types of exercises that each performs should reflect this. To investigate this, Jonason (2007) surveyed 234 male and female college students in Connecticut. He found that male participants focused their energy on gaining muscle mass in their upper body, whereas female participants focused their energy on losing weight. According to this data, Jonason concludes “it appears that men and women adopt sex-appropriate exercise behavior as a method of self-enhancement for intrasexual competition” (p. 5).
Critique. As with other authors in evolutionary psychology, this author downplays culture as an effect of biology rather than a force in and of itself. Consider the following quote from Jonason (2007):
Feminist scholars (e.g.. Wolf. 2002) have argued that women are motivated to lose weight because of seeing thin individuals in the media. Although this is a comforting idea, it only scratches the surface of female preferences for remaining slim. Such explanations only deal with proximate causes and not ultimate ones such as those indicating why women would even pay attention to such messages. Similarly, social-learning theorists have posited that women and men are taught to adopt a culture of thinness and musculature, respectively, by the media, which offers sex-relevant images to men and women… So, while a media exposure hypothesis is relevant, it only touches on the proximal reasons why women would be more motivated to lose weight, and may confuse cause with effect.
This quote reveals the hostile attitude within evolutionary psychology toward the feminist and social perspectives. He simply dismisses the feminist perspective as being confused. This sort of ignorance and hostility is why many scholars and non-scholars enthusiastically reject evolutionary psychology. To not consider the possibility that those 234 Connecticut college students were socialized is absurd and unscientific.
As another example of the sexism within current evolutionary psychology publications, consider the following quote from Kingsley Browne (2006) in his article Sex, Power, and Dominance: The Evolutionary Psychology of Sexual Harassment:
…despite the assumption that prohibitions of discrimination would lead to economic parity between the sexes, men tend – for reasons traceable to our evolutionary heritage – to engage in behaviors that cause them to earn more money than women and lead them to occupy the highest organizational positions at disproportionate rates. (p. 145)
He goes on to claim that sexual harassment is a natural male tendency. Kingsley Browne is a professor of law at Wayne State University and has published a number of books and articles on evolutionary psychology and the inclusion of women in the military and in the workplace. One of his books is titled Co-ed Combat: The New Evidence that Women Shouldn’t Fight the Nation’s Wars.
These sexist mainstream evolutionary psychology ideas have proliferated through our culture. For example, this week, a colleague sent me a clip from Fox News in which male pundits were reacting to a recent finding that in 4 out of 10 U.S. households, women were the primary breadwinner:
When you look at biology, when you look at the natural world, when you look at the roles of a male and a female in society and other animals… the male typically is the dominate role… We… have lost the ability to have complimentary relationships in nuclear families, and it's tearing us apart (Erickson, 2013).
A Challenge to Mainstream Views of Sexual Jealousy
In her article on the evolutionary psychology perspective of sexual jealousy, Christine Harris (2003) asked the question (paraphrased): Do men and women differ in how much they are bothered by a mate’s infidelity and does the existing empirical evidence support claims that men and women have different innate specific evolutionary adaptations that trigger jealousy? Within the field of evolutionary psychology, there is a debate regarding whether men and women have evolved different psychological mechanisms that cause them to respond differently to infidelity. Many within the mainstream evolutionary psychology community (e.g.,
Buss) often propose that gender differences in jealousy are innate. According to this sexually dimorphic hypothesis in evolutionary psychology, natural selection has shaped men to become jealous if they believe their mate is having sex with another woman while women become jealous if they believe their mate is emotionally involved with another woman. They hypothesize that women in a committed relationship feel greater upset over emotional infidelity as opposed to sexual infidelity while men in a committed relationship feel greater upset over sexual infidelity as opposed to emotional infidelity. Although some research has supported this hypothesis, the author points out flaws in the methodology and challenges the validity of the findings.
To examine this issue, Harris (2003) recruited 139 male and 219 female heterosexual college students to anonymously answer questions regarding their feelings about infidelity. When asked in the typical manner of forced-choice questions, the participants responded stereotypically with men being more reactive to sexual infidelity and women being more reactive to emotional infidelity (see figures 1 and 2).
However, when Harris (2003) asked the participants in a different manner, surprising results were found. As seen in figure 3, males and females answered the scaled questions nearly identically.
The questionnaire also asked if the respondent had experienced a partner committing known infidelity, how they felt about the infidelity and how jealous they were regarding their mate’s sexual past (see figures 4 and 5).
Due to these findings, Harris (2003) asserts that when reactions to infidelity were examined more carefully, there was no support for the claim that women and men have evolved different instinctual reactions to infidelity. These findings contradict the commonly held stereotypes about men and women.
Critique. As with other psychological studies, this study was limited to heterosexual college students which provides a threat to external validity. Validity is also threatened by the lack of observational data and the reliance on self-report surveys about hypothetical situations.
Menstrual Cycle and Facial Preferences
Christine Harris (2011) also reconsidered the common wisdom in mainstream evolutionary psychology about women’s menstrual cycle and facial preferences. She discussed the previous research reporting that women prefer more masculine male faces during the fertile phase of their menstrual cycle. She points out that these findings are supposedly a reflection of an evolved evolutionary psychological mating strategy whereby women choose mates of maximum genetic quality when they themselves are likely to conceive. This is based on the common assumption within evolutionary psychology that men with more masculine faces carry better genes and that women instinctually want these genes for their offspring (Harris, 2011). (Note: Christine Harris (2011) points out that there is no evidence that masculine male faces are associated with better genes. Furthermore, aren’t all male faces ‘masculine’? Why are bigger brows considered ‘more male’ than smaller brows?)
To test this assertion, Harris (2011) asked 853 North American adults to evaluate the facial attractiveness of photographed individuals. Contrary to previous research and common understandings, the results did not suggest any greater preference for masculine faces when fertilization was likely.
A Challenge to Gender Differences
Perrin et al. (2011) point out that an evolutionary psychology approach to gender differences in romantic relationships has pervaded the scientific literature. They contend that the mainstream evolutionary psychology view of gender differences has several limitations. They assert that these theories are overreaching and reductionistic in their attempt to explain all gender differences as instinctual. They wisely remind us that these perspectives uphold and reinforce harmful gender stereotypes and gender-based oppression by restricting individual flexibility. These stereotypes include women as being innately emotionally communicative, hyper-emotional, caring, relationship-oriented, and asexual, and men as being innately emotionally inept, hypo-emotional, insensitive, individually-oriented, and overtly sexual. Perrin et al. (2011) argue that research findings supporting gender stereotypes have major limitations. They cite research showing that contextual variables, such as ethnicity, race, and social class, explain more of the variance than gender.
Perrin et al. (2011) attempted to clarify this confusion by testing the general hypothesis that women and men would differ in what they wanted in a romantic relationship. The study involved a sample of 375 students at a southeastern U.S. public university. Their data did not support the gender stereotypes proposed by mainstream evolutionary psychology and popular mythology. Men reported being affected by love and loving behaviors just as much as women which contradicts the stereotype that men do not care about romantic love as much as women do. Also, both men and women reported they were not having as much sex as they desired within their romantic relationships. This finding contradicts the mainstream evolutionary psychology notion that sex is relatively unimportant to women in long-term romantic relationships. In this way, Perrin et al. (2011) provide empirical evidence challenging the viability of the mainstream evolutionary psychology conceptualizations of gender differences, and they provide compelling support for social constructionist and feminist perspectives.
These conclusions are supported by Pedersen, Putcha-Bhagavatula, and Miller (2011) who found that contrary to the popular Sexual Strategies Theory by Buss and Schmitt (1993), men and women do not have distinct mating mechanisms. Specifically, they found that:
…most men are not more apt to spend proportionately more of their mating effort in short-term mating. Nor are they more apt, compared to women, to lower their standards in short-term compared to long-term mating. Furthermore, in short-term mating, most men are not more apt to seek sex if pregnancy is likely… (p. 638).
Pedersen et al. (2011) assert their data is consistent with Attachment Fertility Theory (Miller & Fishkin, as cited in Pedersen, Putcha-Bhagavatula, & Miller, 2011) that postulates more similarity than differences between men and women in their evolved mating mechanisms. They also point out that their findings are consistent with the Gender Similarities Hypothesis which states that men and women are very similar on most variables (Hyde, as cited in Pedersen, Putcha-Bhagavatula, & Miller, 2011).
Upon reflection, I can only think of one possible practical application of evolutionary psychology to my practice as a psychotherapist. When I work with children diagnosed with ADD, I sometimes consider it helpful to provide a positive perspective regarding the child’s inattentive behaviors. I might say, “A hundred thousand years ago, when our species lived on the African savanna, we needed both hunters and gatherers. We needed some people to attend to boring tasks like gathering. And we also needed people with ADD who liked to run, take risks, and hunt. But now, in our modern society, with its school rooms and corporate offices, we have created a world that is not conducive for the hunters. We force them to sit at a desk for several hours and listen to tedious lectures. While the gatherers thrive in school, the hunters are labeled as pathological and given medication.” This perspective argues ADD is a genetic polymorphism that was selected as an adaptive set of psychological mechanisms. Among early tribes of humans, particularly those who migrated out of Africa, it was perhaps beneficial for the gene pool to have some individuals who had preferences and skills for hunting rather than farming.
In my experience, when I provide this perspective, parents breathe a sigh of relief and they begin to see their child in a more positive light. They lower their expectations for straight A’s, and they begin looking at ways for the child to thrive with his or her disposition rather than in spite of it. However, in keeping with the critiques of evolutionary psychology, I must admit that even though this perspective is helpful, it has major scientific flaws. It is perhaps a ‘just-so story’ in that it is an unverifiable and unfalsifiable narrative explanation of ADD, particularly when applied to an individual.
I wrote this article in an attempt to better understand the field of evolutionary psychology. Before researching this topic, I was only vaguely aware of the research, and I was woefully unaware of the critique. The more I read, the more interested I became. And as a result of my temporary obsession, this article is ten times longer than originally intended. Not only are the claims fascinating, but I felt compelled to provide a cogent critique, which led down several rabbit holes.
If those within evolutionary psychology want to be taken seriously by the academic community, they must admit the inherent research limitations and begin to incorporate political and sociocultural factors into their writings. Many of the basic understandings in evolutionary psychology are useful to science and society (e.g., mismatch hypothesis). However, many more of the claims are spurious and even harmful (e.g., claims that men possess innate psychological mechanisms that motivate them to sexually harass women at work). If evolutionary psychology is going to survive, prominent figures within the field must begin differentiating between the spurious claims and the carefully considered claims. When a pundit on Fox News claims than men have evolved to earn more money than women, the media should know who to turn to for wise commentary. As of today, there is no such person.
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