{"id":111,"date":"2017-06-04T16:22:51","date_gmt":"2017-06-04T20:22:51","guid":{"rendered":"https:\/\/pressbooks.bccampus.ca\/kpupsyc1100\/chapter\/evolutionary-theories-in-psychology\/"},"modified":"2017-06-10T12:53:01","modified_gmt":"2017-06-10T16:53:01","slug":"evolutionary-theories-in-psychology","status":"publish","type":"chapter","link":"https:\/\/pressbooks.bccampus.ca\/kpupsyc1100\/chapter\/evolutionary-theories-in-psychology\/","title":{"raw":"Evolutionary Theories in Psychology","rendered":"Evolutionary Theories in Psychology"},"content":{"raw":"<div class=\"textbox learning-objectives\">\r\n<h3>Learning Objectives<\/h3>\r\nBy the end of this section, you will be able to:\r\n<ul>\r\n \t<li>Learn what \u201cevolution\u201d means.<\/li>\r\n \t<li>Define the primary mechanisms by which evolution takes place.<\/li>\r\n \t<li>Identify the two major classes of adaptations.<\/li>\r\n \t<li>Define sexual selection and its two primary processes.<\/li>\r\n \t<li>Define gene selection theory.<\/li>\r\n \t<li>Understand psychological adaptations.<\/li>\r\n \t<li>Identify the core premises of sexual strategies theory.<\/li>\r\n \t<li>Identify the core premises of error management theory, and provide two empirical examples of adaptive cognitive biases.<\/li>\r\n<\/ul>\r\n<\/div>\r\nIf you have ever been on a first date, you\u2019re probably familiar with the anxiety of trying to figure out what clothes to wear or what perfume or cologne to put on. In fact, you may even consider flossing your teeth for the first time all year. When considering why you put in all this work, you probably recognize that you\u2019re doing it to impress the other person. But how did you learn these particular behaviours? Where did you get the idea that a first date should be at a nice restaurant or someplace unique? It is possible that we have been taught these behaviours by observing others. It is also possible, however, that these behaviours\u2014the fancy clothes, the expensive restaurant\u2014are biologically programmed into us. That is, just as peacocks display their feathers to show how attractive they are, or some lizards do push-ups to show how strong they are, when we style our hair or bring a gift to a date, we\u2019re trying to communicate to the other person: \u201cHey, I\u2019m a good mate! Choose me! Choose me!\"\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"644\"]<img src=\"https:\/\/pressbooks.bccampus.ca\/kpupsyc1100\/wp-content\/uploads\/sites\/195\/2017\/06\/original.jpg\" width=\"644\" height=\"800\" alt=\"image\" \/> <em>Figure 7.<\/em> It may seem like just a casual date, but don't doubt that the forces of evolution are hard at work below the surface. [Photo: Molly Ali][\/caption]However, we all know that our ancestors hundreds of thousands of years ago weren\u2019t driving sports cars or wearing designer clothes to attract mates. So how could someone ever say that such behaviours are \u201cbiologically programmed\u201d into us? Well, even though our ancestors might not have been doing these specific actions, these behaviours are the result of the same driving force: the powerful influence of evolution. Yes, evolution\u2014certain traits and behaviours developing over time because they are advantageous to our survival. In the case of dating, doing something like offering a gift might represent more than a nice gesture. Just as chimpanzees will give food to mates to show they can provide for them, when you offer gifts to your dates, you are communicating that you have the money or \u201cresources\u201d to help take care of them. And even though the person receiving the gift may not realize it, the same evolutionary forces are influencing his or her behaviour as well. The receiver of the gift evaluates not only the gift but also the gift-giver's clothes, physical appearance, and many other qualities, to determine whether the individual is a suitable mate. But because these evolutionary processes are hardwired into us, it is easy to overlook their influence.\r\n\r\nTo broaden your understanding of evolutionary processes, this module will present some of the most important elements of evolution as they impact psychology. Evolutionary theory helps us piece together the story of how we humans have prospered. It also helps to explain why we behave as we do on a daily basis in our modern world: why we bring gifts on dates, why we get jealous, why we crave our favourite foods, why we protect our children, and so on. Evolution may seem like a historical concept that applies only to our ancient ancestors but, in truth, it is still very much a part of our modern daily lives.\r\n<h1 id=\"basics-of-evolutionary-theory\">Basics of Evolutionary Theory<\/h1>\r\nEvolution simply means change over time. Many think of evolution as the development of traits and behaviours that allow us to survive this \u201cdog-eat-dog\u201d world, like strong leg muscles to run fast, or fists to punch and defend ourselves. However, physical survival is only important if it eventually contributes to successful reproduction. That is, even if you live to be a 100 years old, if you fail to mate and produce children, your genes will die with your body. Thus, <em>reproductive<\/em> success, not <em>survival<\/em> success, is the engine of evolution by natural selection.\u00a0Every mating success by one person means the loss of a mating opportunity for another. Yet every living human being is an evolutionary success story. Each of us is descended from a long and unbroken line of ancestors who triumphed over others in the struggle to survive (at least long enough to mate) and reproduce. However, in order for our genes to endure over time\u2014to survive harsh climates, to defeat predators\u2014we have inherited adaptive, psychological processes designed to ensure success.\r\n\r\nAt the broadest level, we can think of organisms, including humans, as having two large classes of adaptations\u2014or traits and behaviours that evolved over time to increase our reproductive success. The first class of adaptations are called survival adaptations: mechanisms that helped our ancestors handle the \u201chostile forces of nature.\u201d For example, in order to survive very hot temperatures, we developed sweat glands to cool ourselves. In order to survive very cold temperatures, we developed shivering mechanisms (the speedy contraction and expansion of muscles to produce warmth). Other examples of survival adaptations include developing a craving for fats and sugars, encouraging us to seek out particular foods rich in fats and sugars that keep us going longer during food shortages. Some threats, such as snakes, spiders, darkness, heights, and strangers, often produce fear in us, which encourages us to avoid them and thereby stay safe. These are also examples of survival adaptations. However, all of these adaptations are for physical <em>survival, <\/em>whereas the second class of adaptations are for\u00a0<em>reproduction<\/em>, and help us compete for mates. These adaptations are described in an evolutionary theory proposed by Charles Darwin, called sexual selection theory.\r\n<h1 id=\"sexual-selection-theory\">Sexual Selection Theory<\/h1>\r\nDarwin noticed that there were many traits and behaviours of organisms that could not be explained by \u201csurvival selection.\u201d For example, the brilliant plumage of peacocks should actually lower their rates of survival. That is, the peacocks\u2019 feathers act like a neon sign to predators, advertising \u201cEasy, delicious dinner here!\u201d But if these bright feathers only lower peacocks\u2019 chances at survival, why do they have them? The same can be asked of similar characteristics of other animals, such as the large antlers of male stags or the wattles of roosters, which also seem to be unfavourable to survival. Again, if these traits only make the animals less likely to survive, why did they develop in the first place? And how have these animals continued to survive with these traits over thousands and thousands of years? Darwin\u2019s answer to this conundrum was the theory of sexual selection: the evolution of characteristics, not because of survival advantage, but because of <em>mating<\/em> advantage.\r\n<figure>[caption id=\"\" align=\"aligncenter\" width=\"512\"]<img src=\"https:\/\/pressbooks.bccampus.ca\/kpupsyc1100\/wp-content\/uploads\/sites\/195\/2017\/06\/original-1.jpg\" width=\"512\" height=\"515\" alt=\"image\" \/> <em>Figure 8.<\/em> Modern sports like boxing can be seen as modified\/stylized versions of the evolutionary behaviour of intrasexual competition. [Photo: Dave Hogg][\/caption]<\/figure>\r\nSexual selection occurs through two processes. The first, intrasexual competition, occurs when members of one sex compete against each other, and the winner gets to mate with a member of the opposite sex. Male stags, for example, battle with their antlers, and the winner (often the stronger one with larger antlers) gains mating access to the female. That is, even though large antlers make it harder for the stags to run through the forest and evade predators (which lowers their survival success), they provide the stags with a better chance of attracting a mate (which increases their reproductive success). Similarly, human males sometimes also compete against each other in physical contests: boxing, wrestling, karate, or group-on-group sports, such as football. Even though engaging in these activities poses a \"threat\" to their survival success, as with the stag, the victors are often more attractive to potential mates, increasing their reproductive success. Thus, whatever qualities lead to success in intrasexual competition are then passed on with greater frequency due to their association with greater mating success.\r\n\r\nThe second process of sexual selection is preferential mate choice, also called intersexual selection. In this process, if members of one sex are attracted to certain qualities in mates\u2014such as brilliant plumage, signs of good health, or even intelligence\u2014those desired qualities get passed on in greater numbers, simply because their possessors mate more often. For example, the colourful plumage of peacocks exists due to a long evolutionary history of peahens\u2019 (the term for female peacocks) attraction to males with brilliantly coloured feathers.\r\n\r\nIn all sexually-reproducing species, adaptations in both sexes (males and females) exist due to survival selection and sexual selection. However, unlike other animals where one sex has dominant control over mate choice, humans have \u201cmutual mate choice.\u201d That is, both women and men typically have a say in choosing their mates. And both mates value qualities such as kindness, intelligence, and dependability that are beneficial to long-term relationships\u2014qualities that make good partners and good parents.\r\n<h1 id=\"gene-selection-theory\">Gene Selection Theory<\/h1>\r\nIn modern evolutionary theory, all evolutionary processes boil down to an organism\u2019s genes. Genes are the basic \u201cunits of heredity,\u201d or the information that is passed along in DNA that tells the cells and molecules how to \u201cbuild\u201d the organism and how that organism should behave. Genes that are better able to encourage the organism to reproduce, and thus replicate themselves in the organism\u2019s offspring, have an advantage over competing genes that are less able. For example, take female sloths: In order to attract a mate, they will scream as loudly as they can, to let potential mates know where they are in the thick jungle. Now, consider two types of genes in female sloths: one gene that allows them to scream extremely loudly, and another that only allows them to scream moderately loudly. In this case, the sloth with the gene that allows her to shout louder will attract more mates\u2014increasing reproductive success\u2014which ensures that her genes are more readily passed on than those of the quieter sloth.\r\n\r\nEssentially, genes can boost their own replicative success in two basic ways. First, they can influence the odds for survival and reproduction of the organism they are in (individual reproductive success or fitness\u2014as in the example with the sloths). Second, genes can also influence the organism to help other organisms who also likely contain those genes\u2014known as \u201cgenetic relatives\u201d\u2014to survive and reproduce (which is called inclusive fitness). For example, why do human parents tend to help their own kids with the financial burdens of a college education and not the kids next door? Well, having a college education increases one\u2019s attractiveness to other mates, which increases one\u2019s likelihood for reproducing and passing on genes. And because parents\u2019 genes are in their own children (and not the neighbourhood children), funding their children\u2019s educations increases the likelihood that the parents\u2019 genes will be passed on.\r\n\r\nUnderstanding gene replication is the key to understanding modern evolutionary theory. It also fits well with many evolutionary psychological theories. However, for the time being, we\u2019ll ignore genes and focus primarily on actual adaptations that evolved because they helped our ancestors survive and\/or reproduce.\r\n<h1 id=\"evolutionary-psychology\">Evolutionary Psychology<\/h1>\r\nEvolutionary psychology aims the lens of modern evolutionary theory on the workings of the human mind. It focuses primarily on psychological adaptations: mechanisms of the mind that have evolved to solve specific problems of survival or reproduction. These kinds of adaptations are in contrast to <em>physiological <\/em>adaptations, which are adaptations that occur in the body as a consequence of one\u2019s environment. One example of a physiological adaptation is how our skin makes calluses. First, there is an \u201cinput,\u201d such as repeated friction to the skin on the bottom of our feet from walking. Second, there is a \u201cprocedure,\u201d in which the skin grows new skin cells at the afflicted area. Third, an actual callus forms as an \u201coutput\u201d to protect the underlying tissue\u2014the final outcome of the physiological adaptation (i.e., tougher skin to protect repeatedly scraped areas). On the other hand, a <em>psychological<\/em> adaptation is a development or change of a mechanism in the mind. For example, take sexual jealousy. First, there is an \u201cinput,\u201d such as a romantic partner flirting with a rival. Second, there is a \u201cprocedure,\u201d in which the person evaluates the threat the rival poses to the romantic relationship. Third, there is a behavioural output, which might range from vigilance (e.g., snooping through a partner\u2019s email) to violence (e.g., threatening the rival).\r\n\r\nEvolutionary psychology is fundamentally an <em>interactionist<\/em> framework, or a theory that takes into account multiple factors when determining the outcome. For example, jealousy, like a callus, doesn\u2019t simply pop up out of nowhere. There is an \u201cinteraction\u201d between the environmental trigger (e.g., the flirting; the repeated rubbing of the skin) and the initial response (e.g., evaluation of the flirter\u2019s threat; the forming of new skin cells) to produce the outcome.\r\n\r\nIn evolutionary psychology, culture also has a major effect on psychological adaptations. For example, status within one\u2019s group is important in all cultures for achieving reproductive success, because higher status makes someone more attractive to mates. In individualistic cultures, such as the United States, status is heavily determined by individual accomplishments. But in more collectivist cultures, such as Japan, status is more heavily determined by contributions to the group and by that group\u2019s success. For example, consider a group project. If you were to put in most of the effort on a successful group project, the culture in the United States reinforces the psychological adaptation to try to claim that success for yourself (because individual achievements are rewarded with higher status). However, the culture in Japan reinforces the psychological adaptation to attribute that success to the whole group (because collective achievements are rewarded with higher status). Another example of cultural input is the importance of virginity as a desirable quality for a mate. Cultural norms that advise against premarital sex persuade people to ignore their own basics interests because they know that virginity will make them more attractive marriage partners. Evolutionary psychology, in short, does not predict rigid robotic-like \u201cinstincts.\u201d That is, there isn\u2019t one rule that works all the time. Rather, evolutionary psychology studies flexible, environmentally-connected and culturally-influenced adaptations that vary according to the situation.\r\n\r\nPsychological adaptations are hypothesized to be wide-ranging, and include food preferences, habitat preferences, mate preferences, and specialized fears. These psychological adaptations also include many traits that improve people's ability to live in groups, such as the desire to cooperate and make friends, or the inclination to spot and avoid frauds, punish rivals, establish status hierarchies, nurture children, and help genetic relatives. Research programs in evolutionary psychology develop and empirically test predictions about the nature of psychological adaptations. Below, we highlight a few evolutionary psychological theories and their associated research approaches.\r\n<h1 id=\"sexual-strategies-theory\">Sexual Strategies Theory<\/h1>\r\nSexual strategies theory is based on sexual selection theory. It proposes that humans have evolved a list of different mating strategies, both short-term and long-term, that vary depending on culture, social context, parental influence, and personal mate value (desirability in the \u201cmating market\u201d).\r\n\r\nIn its initial formulation, sexual strategies theory focused on the differences between men and women in mating preferences and strategies (Buss &amp; Schmitt, 1993). It started by looking at the minimum parental investment needed to produce a child. For women, even the minimum investment is significant: after becoming pregnant, they have to carry that child for nine months inside of them. For men, on the other hand, the minimum investment to produce the same child is considerably smaller\u2014simply the act of sex.\r\n<figure>[caption id=\"\" align=\"aligncenter\" width=\"800\"]<img src=\"https:\/\/pressbooks.bccampus.ca\/kpupsyc1100\/wp-content\/uploads\/sites\/195\/2017\/06\/original-2.jpg\" width=\"800\" height=\"532\" alt=\"image\" \/> <em>Figure 9.<\/em> Because women bear responsibility for pregnancy, they may use different sexual selection strategies than men do. [Photo: Emery Co Photo][\/caption]<\/figure>\r\nThese differences in parental investment have an enormous impact on sexual strategies. For a woman, the risks associated with making a poor mating choice is high. She might get pregnant by a man who will not help to support her and her children, or who might have poor-quality genes. And because the stakes are higher for a woman,<em>wise<\/em> mating decisions for her are much more valuable. For men, on the other hand, the need to focus on making wise mating decisions isn\u2019t as important. That is, unlike women, men 1) don\u2019t biologically have the child growing inside of them for nine months, and 2) do not have as high a cultural expectation to raise the child. This logic leads to a powerful set of predictions: In short-term mating, women will likely be choosier than men (because the costs of getting pregnant are so high), while men, on average, will likely engage in more casual sexual activities (because this cost is greatly lessened). Due to this, men will sometimes deceive women about their long-term intentions for the benefit of short-term sex, and men are more likely than women to lower their mating standards for short-term mating situations.\r\n\r\nAn extensive body of empirical evidence supports these and related predictions (Buss &amp; Schmitt, 2011). Men express a desire for a larger number of sex partners than women do. They let less time elapse before seeking sex. They are more willing to consent to sex with strangers and are less likely to require emotional involvement with their sex partners. They have more frequent sexual fantasies and fantasize about a larger variety of sex partners. They are more likely to regret missed sexual opportunities. And they lower their standards in short-term mating, showing a willingness to mate with a larger variety of women as long as the costs and risks are low.\r\n\r\nHowever, in situations where both the man and woman are interested in long-term mating, both sexes tend to invest substantially in the relationship and in their children. In these cases, the theory predicts that both sexes will be extremely choosy when pursuing a long-term mating strategy. Much empirical research supports this prediction, as well. In fact, the qualities women and men generally look for when choosing long-term mates are very similar: both want mates who are intelligent, kind, understanding, healthy, dependable, honest, loyal, loving, and adaptable.\r\n\r\nNonetheless, women and men do differ in their preferences for a few key qualities in long-term mating, because of somewhat distinct adaptive problems. Modern women have inherited the evolutionary trait to desire mates who possess resources, have qualities linked with acquiring resources (e.g., ambition, wealth, industriousness), and are willing to share those resources with them. On the other hand, men more strongly desire youth and health in women, as both are cues to fertility. These male and female differences are universal in humans. They were first documented in 37 different cultures, from Australia to Zambia (Buss, 1989), and have been replicated by dozens of researchers in dozens of additional cultures (for summaries, see Buss, 2012).\r\n\r\nAs we know, though, just because we have these mating preferences (e.g., men with resources; fertile women), people don't always get what they want. There are countless other factors which influence who people ultimately select as their mate. For example, the sex ratio (the percentage of men to women in the mating pool), cultural practices (such as arranged marriages, which inhibit individuals\u2019 freedom to act on their preferred mating strategies), the strategies of others (e.g., if everyone else is pursuing short-term sex, it\u2019s more difficult to pursue a long-term mating strategy), and many others all influence who we select as our mates.\r\n\r\nSexual strategies theory\u2014anchored in sexual selection theory\u2014 predicts specific similarities and differences in men and women\u2019s mating preferences and strategies. Whether we seek short-term or long-term relationships, many personality, social, cultural, and ecological factors will all influence who our partners will be.\r\n<h1 id=\"error-management-theory\">Error Management Theory<\/h1>\r\n<figure>[caption id=\"\" align=\"aligncenter\" width=\"507\"]<img src=\"https:\/\/pressbooks.bccampus.ca\/kpupsyc1100\/wp-content\/uploads\/sites\/195\/2017\/06\/original-3.jpg\" width=\"507\" height=\"800\" alt=\"image\" \/> <em>Figure 10.<\/em> If you were walking in the woods and heard a sound in the bushes you might be startled and act on the worst case scenario\u2014such as the threat of a wild animal\u2014by moving in the opposite direction. This is evolutionary psychology at work, keeping you safe so you can survive and reproduce. [Photo: McMac70][\/caption]<\/figure>\r\nError management theory (EMT) deals with the evolution of how we think, make decisions, and evaluate uncertain situations\u2014that is, situations where there's no clear answer how we should behave. (Haselton &amp; Buss, 2000; Haselton, Nettle, &amp; Andrews, 2005). Consider, for example, walking through the woods at dusk. You hear a rustle in the leaves on the path in front of you. It could be a snake. Or, it could just be the wind blowing the leaves. Because you can't really tell why the leaves rustled, it\u2019s an uncertain situation. The important question then is, what are the costs of errors in judgment? That is, if you conclude that it\u2019s a dangerous snake so you avoid the leaves, the costs are minimal (i.e., you simply make a short detour around them). However, if you assume the leaves are safe and simply walk over them\u2014when in fact it <em>is<\/em> a dangerous snake\u2014the decision could cost you your life.\r\n\r\nNow, think about our evolutionary history and how generation after generation was confronted with similar decisions, where one option had low cost but great reward (walking around the leaves and not getting bitten) and the other had a low reward but high cost (walking through the leaves and getting bitten). These kinds of choices are called \u201ccost asymmetries.\u201d If during our evolutionary history we encountered decisions like these generation after generation, over time an adaptive bias would be created: we would make sure to err in favor of the least costly (in this case, least dangerous) option (e.g., walking around the leaves). To put it another way, EMT predicts that whenever uncertain situations present us with a safer versus more dangerous decision, we will psychologically adapt to prefer choices that minimize the cost of errors.\r\n\r\nEMT is a general evolutionary psychological theory that can be applied to many different domains of our lives, but a specific example of it is the <em>visual descent illusion<\/em>. To illustrate: Have you ever thought it would be no problem to jump off of a ledge, but as soon as you stood up there, it suddenly looked much higher than you thought? The visual descent illusion (Jackson &amp; Cormack, 2008) states that people will overestimate the distance when looking down from a height (compared to looking up) so that people will be especially wary of falling from great heights\u2014which would result in injury or death. Another example of EMT is the <em>auditory looming bias<\/em>: Have you ever noticed how an ambulance seems closer when it's coming toward you, but suddenly seems far away once it's immediately passed? With the auditory looming bias, people overestimate how close objects are when the sound is moving toward them compared to when it is moving away from them. From our evolutionary history, humans learned, \"It\u2019s better to be safe than sorry.\" Therefore, if we think that a threat is closer to us when it\u2019s moving toward us (because it seems louder), we will be quicker to act and escape. In this regard, there may be times we ran away when we didn\u2019t need to (a false alarm), but wasting that time is a less costly mistake than not acting in the first place when a real threat does exist.\r\n\r\nEMT has also been used to predict adaptive biases in the domain of mating. Consider something as simple as a smile. In one case, a smile from a potential mate could be a sign of sexual or romantic interest. On the other hand, it may just signal friendliness. Because of the costs to men of missing out on chances for reproduction, EMT predicts that men have a <em>sexual overperception bias<\/em>: they often misread sexual interest from a woman, when really it\u2019s just a friendly smile or touch. In the mating domain, the sexual overperception bias is one of the best-documented phenomena. It\u2019s been shown in studies in which men and women rated the sexual interest between people in photographs and videotaped interactions. As well, it\u2019s been shown in the laboratory with participants engaging in actual \u201cspeed dating,\u201d where the men interpret sexual interest from the women more often than the women actually intended it (Perilloux, Easton, &amp; Buss, 2012). In short, EMT predicts that men, more than women, will over-infer sexual interest based on minimal cues, and empirical research confirms this adaptive mating bias.\r\n<h1 id=\"conclusion\">Conclusion<\/h1>\r\nSexual strategies theory and error management theory are two evolutionary psychological theories that have received much empirical support from dozens of independent researchers. But, there are many other evolutionary psychological theories, such as social exchange theory for example, that also make predictions about our modern day behavior and preferences, too. The merits of each evolutionary psychological theory, however, must be evaluated separately and treated like any scientific theory. That is, we should only trust their predictions and claims to the extent they are supported by scientific studies. However, even if the theory is scientifically grounded, just because a psychological adaptation was advantageous in our history, it doesn't mean it's still useful today. For example, even though women may have preferred men with resources in generations ago, our modern society has advanced such that these preferences are no longer apt or necessary. Nonetheless, it's important to consider how our evolutionary history has shaped our automatic or \"instinctual\" desires and reflexes of today, so that we can better shape them for the future ahead.\r\n<div class=\"textbox exercises\">\r\n<h3>Activity: Take a Practice Quiz<\/h3>\r\n<a href=\"https:\/\/cerego.com\/sets\/739907\">Click here<\/a> to assess your grasp of the\u00a0information presented on this page.\r\n\r\n<\/div>\r\n<div class=\"textbox key-takeaways\">\r\n<h3>Source<\/h3>\r\n<span class=\"name\">Buss, D. M. (2016). Evolutionary theories in psychology. NOBA Psychology. Retrieved from\u00a0<a href=\"http:\/\/noba.to\/ymcbwrx4\">http:\/\/noba.to\/ymcbwrx4<\/a><\/span>\r\n\r\nNote: This module is\u00a0licensed under a <a href=\"http:\/\/creativecommons.org\/licenses\/by-nc-sa\/4.0\/deed.en_US\" rel=\"license\">Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License<\/a>.\r\n\r\n<\/div>","rendered":"<div class=\"textbox learning-objectives\">\n<h3>Learning Objectives<\/h3>\n<p>By the end of this section, you will be able to:<\/p>\n<ul>\n<li>Learn what \u201cevolution\u201d means.<\/li>\n<li>Define the primary mechanisms by which evolution takes place.<\/li>\n<li>Identify the two major classes of adaptations.<\/li>\n<li>Define sexual selection and its two primary processes.<\/li>\n<li>Define gene selection theory.<\/li>\n<li>Understand psychological adaptations.<\/li>\n<li>Identify the core premises of sexual strategies theory.<\/li>\n<li>Identify the core premises of error management theory, and provide two empirical examples of adaptive cognitive biases.<\/li>\n<\/ul>\n<\/div>\n<p>If you have ever been on a first date, you\u2019re probably familiar with the anxiety of trying to figure out what clothes to wear or what perfume or cologne to put on. In fact, you may even consider flossing your teeth for the first time all year. When considering why you put in all this work, you probably recognize that you\u2019re doing it to impress the other person. But how did you learn these particular behaviours? Where did you get the idea that a first date should be at a nice restaurant or someplace unique? It is possible that we have been taught these behaviours by observing others. It is also possible, however, that these behaviours\u2014the fancy clothes, the expensive restaurant\u2014are biologically programmed into us. That is, just as peacocks display their feathers to show how attractive they are, or some lizards do push-ups to show how strong they are, when we style our hair or bring a gift to a date, we\u2019re trying to communicate to the other person: \u201cHey, I\u2019m a good mate! Choose me! Choose me!&#8221;<\/p>\n<figure style=\"width: 644px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/pressbooks.bccampus.ca\/kpupsyc1100\/wp-content\/uploads\/sites\/195\/2017\/06\/original.jpg\" width=\"644\" height=\"800\" alt=\"image\" \/><figcaption class=\"wp-caption-text\"><em>Figure 7.<\/em> It may seem like just a casual date, but don&#8217;t doubt that the forces of evolution are hard at work below the surface. [Photo: Molly Ali]<\/figcaption><\/figure>\n<p>However, we all know that our ancestors hundreds of thousands of years ago weren\u2019t driving sports cars or wearing designer clothes to attract mates. So how could someone ever say that such behaviours are \u201cbiologically programmed\u201d into us? Well, even though our ancestors might not have been doing these specific actions, these behaviours are the result of the same driving force: the powerful influence of evolution. Yes, evolution\u2014certain traits and behaviours developing over time because they are advantageous to our survival. In the case of dating, doing something like offering a gift might represent more than a nice gesture. Just as chimpanzees will give food to mates to show they can provide for them, when you offer gifts to your dates, you are communicating that you have the money or \u201cresources\u201d to help take care of them. And even though the person receiving the gift may not realize it, the same evolutionary forces are influencing his or her behaviour as well. The receiver of the gift evaluates not only the gift but also the gift-giver&#8217;s clothes, physical appearance, and many other qualities, to determine whether the individual is a suitable mate. But because these evolutionary processes are hardwired into us, it is easy to overlook their influence.<\/p>\n<p>To broaden your understanding of evolutionary processes, this module will present some of the most important elements of evolution as they impact psychology. Evolutionary theory helps us piece together the story of how we humans have prospered. It also helps to explain why we behave as we do on a daily basis in our modern world: why we bring gifts on dates, why we get jealous, why we crave our favourite foods, why we protect our children, and so on. Evolution may seem like a historical concept that applies only to our ancient ancestors but, in truth, it is still very much a part of our modern daily lives.<\/p>\n<h1 id=\"basics-of-evolutionary-theory\">Basics of Evolutionary Theory<\/h1>\n<p>Evolution simply means change over time. Many think of evolution as the development of traits and behaviours that allow us to survive this \u201cdog-eat-dog\u201d world, like strong leg muscles to run fast, or fists to punch and defend ourselves. However, physical survival is only important if it eventually contributes to successful reproduction. That is, even if you live to be a 100 years old, if you fail to mate and produce children, your genes will die with your body. Thus, <em>reproductive<\/em> success, not <em>survival<\/em> success, is the engine of evolution by natural selection.\u00a0Every mating success by one person means the loss of a mating opportunity for another. Yet every living human being is an evolutionary success story. Each of us is descended from a long and unbroken line of ancestors who triumphed over others in the struggle to survive (at least long enough to mate) and reproduce. However, in order for our genes to endure over time\u2014to survive harsh climates, to defeat predators\u2014we have inherited adaptive, psychological processes designed to ensure success.<\/p>\n<p>At the broadest level, we can think of organisms, including humans, as having two large classes of adaptations\u2014or traits and behaviours that evolved over time to increase our reproductive success. The first class of adaptations are called survival adaptations: mechanisms that helped our ancestors handle the \u201chostile forces of nature.\u201d For example, in order to survive very hot temperatures, we developed sweat glands to cool ourselves. In order to survive very cold temperatures, we developed shivering mechanisms (the speedy contraction and expansion of muscles to produce warmth). Other examples of survival adaptations include developing a craving for fats and sugars, encouraging us to seek out particular foods rich in fats and sugars that keep us going longer during food shortages. Some threats, such as snakes, spiders, darkness, heights, and strangers, often produce fear in us, which encourages us to avoid them and thereby stay safe. These are also examples of survival adaptations. However, all of these adaptations are for physical <em>survival, <\/em>whereas the second class of adaptations are for\u00a0<em>reproduction<\/em>, and help us compete for mates. These adaptations are described in an evolutionary theory proposed by Charles Darwin, called sexual selection theory.<\/p>\n<h1 id=\"sexual-selection-theory\">Sexual Selection Theory<\/h1>\n<p>Darwin noticed that there were many traits and behaviours of organisms that could not be explained by \u201csurvival selection.\u201d For example, the brilliant plumage of peacocks should actually lower their rates of survival. That is, the peacocks\u2019 feathers act like a neon sign to predators, advertising \u201cEasy, delicious dinner here!\u201d But if these bright feathers only lower peacocks\u2019 chances at survival, why do they have them? The same can be asked of similar characteristics of other animals, such as the large antlers of male stags or the wattles of roosters, which also seem to be unfavourable to survival. Again, if these traits only make the animals less likely to survive, why did they develop in the first place? And how have these animals continued to survive with these traits over thousands and thousands of years? Darwin\u2019s answer to this conundrum was the theory of sexual selection: the evolution of characteristics, not because of survival advantage, but because of <em>mating<\/em> advantage.<\/p>\n<figure>\n<figure style=\"width: 512px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/pressbooks.bccampus.ca\/kpupsyc1100\/wp-content\/uploads\/sites\/195\/2017\/06\/original-1.jpg\" width=\"512\" height=\"515\" alt=\"image\" \/><figcaption class=\"wp-caption-text\"><em>Figure 8.<\/em> Modern sports like boxing can be seen as modified\/stylized versions of the evolutionary behaviour of intrasexual competition. [Photo: Dave Hogg]<\/figcaption><\/figure>\n<\/figure>\n<p>Sexual selection occurs through two processes. The first, intrasexual competition, occurs when members of one sex compete against each other, and the winner gets to mate with a member of the opposite sex. Male stags, for example, battle with their antlers, and the winner (often the stronger one with larger antlers) gains mating access to the female. That is, even though large antlers make it harder for the stags to run through the forest and evade predators (which lowers their survival success), they provide the stags with a better chance of attracting a mate (which increases their reproductive success). Similarly, human males sometimes also compete against each other in physical contests: boxing, wrestling, karate, or group-on-group sports, such as football. Even though engaging in these activities poses a &#8220;threat&#8221; to their survival success, as with the stag, the victors are often more attractive to potential mates, increasing their reproductive success. Thus, whatever qualities lead to success in intrasexual competition are then passed on with greater frequency due to their association with greater mating success.<\/p>\n<p>The second process of sexual selection is preferential mate choice, also called intersexual selection. In this process, if members of one sex are attracted to certain qualities in mates\u2014such as brilliant plumage, signs of good health, or even intelligence\u2014those desired qualities get passed on in greater numbers, simply because their possessors mate more often. For example, the colourful plumage of peacocks exists due to a long evolutionary history of peahens\u2019 (the term for female peacocks) attraction to males with brilliantly coloured feathers.<\/p>\n<p>In all sexually-reproducing species, adaptations in both sexes (males and females) exist due to survival selection and sexual selection. However, unlike other animals where one sex has dominant control over mate choice, humans have \u201cmutual mate choice.\u201d That is, both women and men typically have a say in choosing their mates. And both mates value qualities such as kindness, intelligence, and dependability that are beneficial to long-term relationships\u2014qualities that make good partners and good parents.<\/p>\n<h1 id=\"gene-selection-theory\">Gene Selection Theory<\/h1>\n<p>In modern evolutionary theory, all evolutionary processes boil down to an organism\u2019s genes. Genes are the basic \u201cunits of heredity,\u201d or the information that is passed along in DNA that tells the cells and molecules how to \u201cbuild\u201d the organism and how that organism should behave. Genes that are better able to encourage the organism to reproduce, and thus replicate themselves in the organism\u2019s offspring, have an advantage over competing genes that are less able. For example, take female sloths: In order to attract a mate, they will scream as loudly as they can, to let potential mates know where they are in the thick jungle. Now, consider two types of genes in female sloths: one gene that allows them to scream extremely loudly, and another that only allows them to scream moderately loudly. In this case, the sloth with the gene that allows her to shout louder will attract more mates\u2014increasing reproductive success\u2014which ensures that her genes are more readily passed on than those of the quieter sloth.<\/p>\n<p>Essentially, genes can boost their own replicative success in two basic ways. First, they can influence the odds for survival and reproduction of the organism they are in (individual reproductive success or fitness\u2014as in the example with the sloths). Second, genes can also influence the organism to help other organisms who also likely contain those genes\u2014known as \u201cgenetic relatives\u201d\u2014to survive and reproduce (which is called inclusive fitness). For example, why do human parents tend to help their own kids with the financial burdens of a college education and not the kids next door? Well, having a college education increases one\u2019s attractiveness to other mates, which increases one\u2019s likelihood for reproducing and passing on genes. And because parents\u2019 genes are in their own children (and not the neighbourhood children), funding their children\u2019s educations increases the likelihood that the parents\u2019 genes will be passed on.<\/p>\n<p>Understanding gene replication is the key to understanding modern evolutionary theory. It also fits well with many evolutionary psychological theories. However, for the time being, we\u2019ll ignore genes and focus primarily on actual adaptations that evolved because they helped our ancestors survive and\/or reproduce.<\/p>\n<h1 id=\"evolutionary-psychology\">Evolutionary Psychology<\/h1>\n<p>Evolutionary psychology aims the lens of modern evolutionary theory on the workings of the human mind. It focuses primarily on psychological adaptations: mechanisms of the mind that have evolved to solve specific problems of survival or reproduction. These kinds of adaptations are in contrast to <em>physiological <\/em>adaptations, which are adaptations that occur in the body as a consequence of one\u2019s environment. One example of a physiological adaptation is how our skin makes calluses. First, there is an \u201cinput,\u201d such as repeated friction to the skin on the bottom of our feet from walking. Second, there is a \u201cprocedure,\u201d in which the skin grows new skin cells at the afflicted area. Third, an actual callus forms as an \u201coutput\u201d to protect the underlying tissue\u2014the final outcome of the physiological adaptation (i.e., tougher skin to protect repeatedly scraped areas). On the other hand, a <em>psychological<\/em> adaptation is a development or change of a mechanism in the mind. For example, take sexual jealousy. First, there is an \u201cinput,\u201d such as a romantic partner flirting with a rival. Second, there is a \u201cprocedure,\u201d in which the person evaluates the threat the rival poses to the romantic relationship. Third, there is a behavioural output, which might range from vigilance (e.g., snooping through a partner\u2019s email) to violence (e.g., threatening the rival).<\/p>\n<p>Evolutionary psychology is fundamentally an <em>interactionist<\/em> framework, or a theory that takes into account multiple factors when determining the outcome. For example, jealousy, like a callus, doesn\u2019t simply pop up out of nowhere. There is an \u201cinteraction\u201d between the environmental trigger (e.g., the flirting; the repeated rubbing of the skin) and the initial response (e.g., evaluation of the flirter\u2019s threat; the forming of new skin cells) to produce the outcome.<\/p>\n<p>In evolutionary psychology, culture also has a major effect on psychological adaptations. For example, status within one\u2019s group is important in all cultures for achieving reproductive success, because higher status makes someone more attractive to mates. In individualistic cultures, such as the United States, status is heavily determined by individual accomplishments. But in more collectivist cultures, such as Japan, status is more heavily determined by contributions to the group and by that group\u2019s success. For example, consider a group project. If you were to put in most of the effort on a successful group project, the culture in the United States reinforces the psychological adaptation to try to claim that success for yourself (because individual achievements are rewarded with higher status). However, the culture in Japan reinforces the psychological adaptation to attribute that success to the whole group (because collective achievements are rewarded with higher status). Another example of cultural input is the importance of virginity as a desirable quality for a mate. Cultural norms that advise against premarital sex persuade people to ignore their own basics interests because they know that virginity will make them more attractive marriage partners. Evolutionary psychology, in short, does not predict rigid robotic-like \u201cinstincts.\u201d That is, there isn\u2019t one rule that works all the time. Rather, evolutionary psychology studies flexible, environmentally-connected and culturally-influenced adaptations that vary according to the situation.<\/p>\n<p>Psychological adaptations are hypothesized to be wide-ranging, and include food preferences, habitat preferences, mate preferences, and specialized fears. These psychological adaptations also include many traits that improve people&#8217;s ability to live in groups, such as the desire to cooperate and make friends, or the inclination to spot and avoid frauds, punish rivals, establish status hierarchies, nurture children, and help genetic relatives. Research programs in evolutionary psychology develop and empirically test predictions about the nature of psychological adaptations. Below, we highlight a few evolutionary psychological theories and their associated research approaches.<\/p>\n<h1 id=\"sexual-strategies-theory\">Sexual Strategies Theory<\/h1>\n<p>Sexual strategies theory is based on sexual selection theory. It proposes that humans have evolved a list of different mating strategies, both short-term and long-term, that vary depending on culture, social context, parental influence, and personal mate value (desirability in the \u201cmating market\u201d).<\/p>\n<p>In its initial formulation, sexual strategies theory focused on the differences between men and women in mating preferences and strategies (Buss &amp; Schmitt, 1993). It started by looking at the minimum parental investment needed to produce a child. For women, even the minimum investment is significant: after becoming pregnant, they have to carry that child for nine months inside of them. For men, on the other hand, the minimum investment to produce the same child is considerably smaller\u2014simply the act of sex.<\/p>\n<figure>\n<figure style=\"width: 800px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/pressbooks.bccampus.ca\/kpupsyc1100\/wp-content\/uploads\/sites\/195\/2017\/06\/original-2.jpg\" width=\"800\" height=\"532\" alt=\"image\" \/><figcaption class=\"wp-caption-text\"><em>Figure 9.<\/em> Because women bear responsibility for pregnancy, they may use different sexual selection strategies than men do. [Photo: Emery Co Photo]<\/figcaption><\/figure>\n<\/figure>\n<p>These differences in parental investment have an enormous impact on sexual strategies. For a woman, the risks associated with making a poor mating choice is high. She might get pregnant by a man who will not help to support her and her children, or who might have poor-quality genes. And because the stakes are higher for a woman,<em>wise<\/em> mating decisions for her are much more valuable. For men, on the other hand, the need to focus on making wise mating decisions isn\u2019t as important. That is, unlike women, men 1) don\u2019t biologically have the child growing inside of them for nine months, and 2) do not have as high a cultural expectation to raise the child. This logic leads to a powerful set of predictions: In short-term mating, women will likely be choosier than men (because the costs of getting pregnant are so high), while men, on average, will likely engage in more casual sexual activities (because this cost is greatly lessened). Due to this, men will sometimes deceive women about their long-term intentions for the benefit of short-term sex, and men are more likely than women to lower their mating standards for short-term mating situations.<\/p>\n<p>An extensive body of empirical evidence supports these and related predictions (Buss &amp; Schmitt, 2011). Men express a desire for a larger number of sex partners than women do. They let less time elapse before seeking sex. They are more willing to consent to sex with strangers and are less likely to require emotional involvement with their sex partners. They have more frequent sexual fantasies and fantasize about a larger variety of sex partners. They are more likely to regret missed sexual opportunities. And they lower their standards in short-term mating, showing a willingness to mate with a larger variety of women as long as the costs and risks are low.<\/p>\n<p>However, in situations where both the man and woman are interested in long-term mating, both sexes tend to invest substantially in the relationship and in their children. In these cases, the theory predicts that both sexes will be extremely choosy when pursuing a long-term mating strategy. Much empirical research supports this prediction, as well. In fact, the qualities women and men generally look for when choosing long-term mates are very similar: both want mates who are intelligent, kind, understanding, healthy, dependable, honest, loyal, loving, and adaptable.<\/p>\n<p>Nonetheless, women and men do differ in their preferences for a few key qualities in long-term mating, because of somewhat distinct adaptive problems. Modern women have inherited the evolutionary trait to desire mates who possess resources, have qualities linked with acquiring resources (e.g., ambition, wealth, industriousness), and are willing to share those resources with them. On the other hand, men more strongly desire youth and health in women, as both are cues to fertility. These male and female differences are universal in humans. They were first documented in 37 different cultures, from Australia to Zambia (Buss, 1989), and have been replicated by dozens of researchers in dozens of additional cultures (for summaries, see Buss, 2012).<\/p>\n<p>As we know, though, just because we have these mating preferences (e.g., men with resources; fertile women), people don&#8217;t always get what they want. There are countless other factors which influence who people ultimately select as their mate. For example, the sex ratio (the percentage of men to women in the mating pool), cultural practices (such as arranged marriages, which inhibit individuals\u2019 freedom to act on their preferred mating strategies), the strategies of others (e.g., if everyone else is pursuing short-term sex, it\u2019s more difficult to pursue a long-term mating strategy), and many others all influence who we select as our mates.<\/p>\n<p>Sexual strategies theory\u2014anchored in sexual selection theory\u2014 predicts specific similarities and differences in men and women\u2019s mating preferences and strategies. Whether we seek short-term or long-term relationships, many personality, social, cultural, and ecological factors will all influence who our partners will be.<\/p>\n<h1 id=\"error-management-theory\">Error Management Theory<\/h1>\n<figure>\n<figure style=\"width: 507px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/pressbooks.bccampus.ca\/kpupsyc1100\/wp-content\/uploads\/sites\/195\/2017\/06\/original-3.jpg\" width=\"507\" height=\"800\" alt=\"image\" \/><figcaption class=\"wp-caption-text\"><em>Figure 10.<\/em> If you were walking in the woods and heard a sound in the bushes you might be startled and act on the worst case scenario\u2014such as the threat of a wild animal\u2014by moving in the opposite direction. This is evolutionary psychology at work, keeping you safe so you can survive and reproduce. [Photo: McMac70]<\/figcaption><\/figure>\n<\/figure>\n<p>Error management theory (EMT) deals with the evolution of how we think, make decisions, and evaluate uncertain situations\u2014that is, situations where there&#8217;s no clear answer how we should behave. (Haselton &amp; Buss, 2000; Haselton, Nettle, &amp; Andrews, 2005). Consider, for example, walking through the woods at dusk. You hear a rustle in the leaves on the path in front of you. It could be a snake. Or, it could just be the wind blowing the leaves. Because you can&#8217;t really tell why the leaves rustled, it\u2019s an uncertain situation. The important question then is, what are the costs of errors in judgment? That is, if you conclude that it\u2019s a dangerous snake so you avoid the leaves, the costs are minimal (i.e., you simply make a short detour around them). However, if you assume the leaves are safe and simply walk over them\u2014when in fact it <em>is<\/em> a dangerous snake\u2014the decision could cost you your life.<\/p>\n<p>Now, think about our evolutionary history and how generation after generation was confronted with similar decisions, where one option had low cost but great reward (walking around the leaves and not getting bitten) and the other had a low reward but high cost (walking through the leaves and getting bitten). These kinds of choices are called \u201ccost asymmetries.\u201d If during our evolutionary history we encountered decisions like these generation after generation, over time an adaptive bias would be created: we would make sure to err in favor of the least costly (in this case, least dangerous) option (e.g., walking around the leaves). To put it another way, EMT predicts that whenever uncertain situations present us with a safer versus more dangerous decision, we will psychologically adapt to prefer choices that minimize the cost of errors.<\/p>\n<p>EMT is a general evolutionary psychological theory that can be applied to many different domains of our lives, but a specific example of it is the <em>visual descent illusion<\/em>. To illustrate: Have you ever thought it would be no problem to jump off of a ledge, but as soon as you stood up there, it suddenly looked much higher than you thought? The visual descent illusion (Jackson &amp; Cormack, 2008) states that people will overestimate the distance when looking down from a height (compared to looking up) so that people will be especially wary of falling from great heights\u2014which would result in injury or death. Another example of EMT is the <em>auditory looming bias<\/em>: Have you ever noticed how an ambulance seems closer when it&#8217;s coming toward you, but suddenly seems far away once it&#8217;s immediately passed? With the auditory looming bias, people overestimate how close objects are when the sound is moving toward them compared to when it is moving away from them. From our evolutionary history, humans learned, &#8220;It\u2019s better to be safe than sorry.&#8221; Therefore, if we think that a threat is closer to us when it\u2019s moving toward us (because it seems louder), we will be quicker to act and escape. In this regard, there may be times we ran away when we didn\u2019t need to (a false alarm), but wasting that time is a less costly mistake than not acting in the first place when a real threat does exist.<\/p>\n<p>EMT has also been used to predict adaptive biases in the domain of mating. Consider something as simple as a smile. In one case, a smile from a potential mate could be a sign of sexual or romantic interest. On the other hand, it may just signal friendliness. Because of the costs to men of missing out on chances for reproduction, EMT predicts that men have a <em>sexual overperception bias<\/em>: they often misread sexual interest from a woman, when really it\u2019s just a friendly smile or touch. In the mating domain, the sexual overperception bias is one of the best-documented phenomena. It\u2019s been shown in studies in which men and women rated the sexual interest between people in photographs and videotaped interactions. As well, it\u2019s been shown in the laboratory with participants engaging in actual \u201cspeed dating,\u201d where the men interpret sexual interest from the women more often than the women actually intended it (Perilloux, Easton, &amp; Buss, 2012). In short, EMT predicts that men, more than women, will over-infer sexual interest based on minimal cues, and empirical research confirms this adaptive mating bias.<\/p>\n<h1 id=\"conclusion\">Conclusion<\/h1>\n<p>Sexual strategies theory and error management theory are two evolutionary psychological theories that have received much empirical support from dozens of independent researchers. But, there are many other evolutionary psychological theories, such as social exchange theory for example, that also make predictions about our modern day behavior and preferences, too. The merits of each evolutionary psychological theory, however, must be evaluated separately and treated like any scientific theory. That is, we should only trust their predictions and claims to the extent they are supported by scientific studies. However, even if the theory is scientifically grounded, just because a psychological adaptation was advantageous in our history, it doesn&#8217;t mean it&#8217;s still useful today. For example, even though women may have preferred men with resources in generations ago, our modern society has advanced such that these preferences are no longer apt or necessary. Nonetheless, it&#8217;s important to consider how our evolutionary history has shaped our automatic or &#8220;instinctual&#8221; desires and reflexes of today, so that we can better shape them for the future ahead.<\/p>\n<div class=\"textbox exercises\">\n<h3>Activity: Take a Practice Quiz<\/h3>\n<p><a href=\"https:\/\/cerego.com\/sets\/739907\">Click here<\/a> to assess your grasp of the\u00a0information presented on this page.<\/p>\n<\/div>\n<div class=\"textbox key-takeaways\">\n<h3>Source<\/h3>\n<p><span class=\"name\">Buss, D. M. (2016). Evolutionary theories in psychology. NOBA Psychology. Retrieved from\u00a0<a href=\"http:\/\/noba.to\/ymcbwrx4\">http:\/\/noba.to\/ymcbwrx4<\/a><\/span><\/p>\n<p>Note: This module is\u00a0licensed under a <a href=\"http:\/\/creativecommons.org\/licenses\/by-nc-sa\/4.0\/deed.en_US\" rel=\"license\">Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License<\/a>.<\/p>\n<\/div>\n","protected":false},"author":28,"menu_order":2,"template":"","meta":{"pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"class_list":["post-111","chapter","type-chapter","status-publish","hentry"],"part":99,"_links":{"self":[{"href":"https:\/\/pressbooks.bccampus.ca\/kpupsyc1100\/wp-json\/pressbooks\/v2\/chapters\/111","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pressbooks.bccampus.ca\/kpupsyc1100\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/pressbooks.bccampus.ca\/kpupsyc1100\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/kpupsyc1100\/wp-json\/wp\/v2\/users\/28"}],"version-history":[{"count":4,"href":"https:\/\/pressbooks.bccampus.ca\/kpupsyc1100\/wp-json\/pressbooks\/v2\/chapters\/111\/revisions"}],"predecessor-version":[{"id":381,"href":"https:\/\/pressbooks.bccampus.ca\/kpupsyc1100\/wp-json\/pressbooks\/v2\/chapters\/111\/revisions\/381"}],"part":[{"href":"https:\/\/pressbooks.bccampus.ca\/kpupsyc1100\/wp-json\/pressbooks\/v2\/parts\/99"}],"metadata":[{"href":"https:\/\/pressbooks.bccampus.ca\/kpupsyc1100\/wp-json\/pressbooks\/v2\/chapters\/111\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/pressbooks.bccampus.ca\/kpupsyc1100\/wp-json\/wp\/v2\/media?parent=111"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/kpupsyc1100\/wp-json\/pressbooks\/v2\/chapter-type?post=111"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/kpupsyc1100\/wp-json\/wp\/v2\/contributor?post=111"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/kpupsyc1100\/wp-json\/wp\/v2\/license?post=111"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}