Abstract
Perhaps the most fundamental question in psychology is why people do the things they do. Douglas Kenrick and Vladas Griskevicius discuss decision-making and why people make apparently irrational choices in their book The Rational Animal: How Evolution Made us Smarter than we Think. With their years of experience in evolutionary psychology, they examine decision-making through an evolutionary lens. To illustrate the points that are made, the authors use examples often involving individuals and situations that are well known (e.g., MC Hammer, Steve Jobs, the Disney brothers). Most chapters are opened with extreme statements which are slowly unpacked throughout the chapter by applying the main concept of the chapter to the statement. In this fashion the book gives answers to outlandish statements (e.g., why uneducated tribes people from the Amazon jungle easily solve logical puzzles that sophisticated Harvard students have problems with, why there are people that go from rags to riches, and why people in Africa choose to starve), that are often not as bad as they seem. The illustrative examples, extreme statements, and more informal style of writing makes The Rational Animal an easy-yet-informative read about a rather new way of looking at decision-making.
Kenrick and Griskevicius have one overarching point. Rational choice theory or neo-classical and behavioral economics models of decision-making are insufficient because the former does not fit with the numerous apparent violations of rational choice that behavioral economists have noted and the latter is insufficient because it presumes that decisions are driven solely by emotional eddies in people. The authors suggest that both are incomplete and essentially superficial ways at looking at decision-making. As is the case for most evolutionary work, they argue that we must look deeper; we must look underneath the surface so that we can learn the adaptive reasons behind our apparent irrationality.
To advance this case, they make two arguments about human decision-making. Firstly, many of our cognitive and behavioral biases have deeper evolutionary functions, which on the surface may make an action look ridiculous, but on a deeper level will show an evolutionary function. Secondly, because there are different subselves for important evolutionary challenges our ancestors had to face, understanding the adaptive function of a certain tendency puts us in a better position to predict when the tendency will be stronger than other times. Our ancestors had to make decisions in sometimes incompatible ways, using different psychological systems, termed subselves, to meet evolutionary challenges. These subselves led to apparently inconsistent and sometimes unhealthy behavior depending on the evolutionary challenge being faced. For instance, when the self-protection subself is activated, people are more loss aversive than usual. Loss aversion was adaptive for ancestral challenges related to survival, because a sudden loss of food makes a bigger risk impact than a sudden upturn of food. On the other hand, when the mate-acquisition subself is primed, the importance of gains becomes higher than that of losses, because gaining a mate is required for gene survival. With these arguments the authors challenge the behavioral economics and rational economics views. Behavioral economics argue that irrational behavior is simply something stupid and funny people tend to do. Rational economics on the other hand, view people as rational, with the idea that people make decisions based on what is in it for them. In The Rational Animal it is argued that behavior is often driven by deep-seated evolutionary reasons; people are motivated to serve their subselves thereby increasing their inclusive fitness depending on the active subself. The authors introduce in Chapter 1 how choices made in a modern world are made through the ancestral mechanisms that operate outside of our conscious mind, which leads to seemingly irrational decisions. In Chapter 2 they establish how these decisions vary. Initially these concepts seem confusing, but the applied examples help in showing that the two main arguments are based on two basic evolutionary principles: that human decision-making serves evolutionary goals, and that decision-making is designed to achieve several evolutionary goals. Without a defined structure to the book, the authors use the following chapters to apply these points to familiar evolutionary concepts and new research in evolutionary psychology.
Throughout the book, the authors build on the idea that an adaptive decision is not the same as an accurate decision. Decisions may seem foolish or biased, but make good evolutionary sense. To explain this in more detail the smoke detector analogy is used. People tend to get annoyed by a sensitive smoke alarm, which goes off whenever it senses smoke from sources that cause no harm, like an oven. However, people would still rather get annoyed than take the batteries out of the smoke detector and risk undetected fire. A false alarm is to make sure real dangers or reasons for action are not missed. When missed it would result in either incompetence or loss of gene reproduction. This does not only work with danger, but also with a variety of subselves and scenarios such as perceived sexual interest. The mate-acquisition subself helps men overestimate perceived sexual interest (false alarm). This may seem foolish, as it makes men think women hit on them when women are just being friendly. However, overestimation of perceived sexual interest is better than not perceiving sexual interest (missing the alarm), which would result in missing out on a potential mate all together. The deep rationality to the apparently irrational is a mismatch between the modern world we live in and the brains we use that are evolved to solve ancestral problems. The authors explain that not all errors in decision-making have evolutionary reasons behind them, but may stem from thinking in ways that are evolutionarily novel, like writing rather than speaking, or thinking in percentiles rather than ratios. Uneducated tribesmen are shown to solve logical puzzles more easily than Harvard students, because they think about logical puzzles in natural ways. When math problems are reframed into a natural problem, as tribesmen automatically do, people are more likely to answer the math problem correctly. The authors show that when people make mistakes they should not simply be considered as morons, and provide a novel rational choice model based on evolutionary theory to explain these mistakes.
The model detailed by Kenrick and Griskevicius also provides an explanation to why people prefer different decisions depending on the situation. Each subself in a person calculates the cost and benefit according to their evolutionary priority, which cover the important ancestral evolutionary challenges. The authors examine how men and women besides their standard subselves also have his and her subselves, based on the differences in reproductive strategies. These differences in subselves make men and women react either differently, or the same but with different underlying reasons, regardless of the same subself being activated. For example, when men tip generously, they want to advertise their wealth, but when women tip high, they show their caring nature. These subselves are shown to be activated through priming. The authors examine how “parasites” ranging from caring politicians to helpful individuals or corporations are aware of our evolutionary needs and how to activate them, and take advantage of that knowledge. For example, shoes originally function to protect the bottom of our feet, not something that people would pay highly for. But when shoes, like dress shoes, also cover ancestral needs, such as gaining status or mate-acquisition, people are suddenly happy to pay top prices. The whole history of the jewellery business is based on a similar exploitation of ancestral needs. Originally jewellery has no direct function, but smart marketing has created jewellery to cover every type of ancestral need: jewellery for mate-acquisition, mate-retention, status, and even self-protection and disease avoidance subselves (e.g., “this necklace protects you from evil spirits”). To prevent falling for these tricks the authors propose in a self-help book style that it is important to see how many subselves benefit the decision to be made if you want to make smart choices. They show that decision-making is not as straight forward as considered by some decision-making models.
In essence the title is a misnomer. They are not advancing a rational model in the traditional sense of the word “rational” but, instead, they show how we can make rational sense out of apparent irrationality. This is carried out on the back of two main concepts: how human decision-making, even the seemingly irrational, has evolutionary reasons, and how everyone has multiple subselves to achieve different evolutionary goals. Kenrick and Griskevicius put these ideas forward through an intentionally non-scientific writing style, using popular examples, yet reinforced by new research. Indeed, anyone who knows the authors will hear their voices coming through the pages of the book. These elements create a book that would appeal to a varied audience. The more advanced reader will be informed of new ways of looking at decision-making. While the book goes over a range of known evolutionary concepts it includes in-depth ideas, providing exciting new research directions. On the other hand, the book would also be enjoyable for people new to evolutionary theory. The book introduces a variety of concepts in a clear and cohesive way, using popular references to introduce and explain the concepts.
Kenrick and Griskevicius challenge the concept of the behavioral economist who argues that all irrational behavior is simply stupid, and of the rational economist who says that all people make decisions in terms of rational self-interest. The authors show the economists are not completely wrong, but have to incorporate why people have different preferences of decisions, depending on relevant evolutionary contexts. Human behavior may seem foolish, but beneath the surface there is a deeply rational reason, which may vary depending on the evolutionary beneficial subself activated. Kenrick and Griskevicius provide a cohesive description of novel evolutionary insights into decision-making in a range of concepts, with a style open to a wide audience.