Readers who are familiar with the better-known claims of evolutionary psychology (EP) will recognize many of those core ideas in this practical, informative, and entertaining book.  This work extends the usefulness of other recent books on human decision-making by tightly weaving together the perspectives of psychology (Kenrick) and marketing (Griskevicius).  The book thoroughly supports the authors’ claims that although human decision-making processes may not, at first glance, seem consistently rational, the unconscious underpinnings that drive our decision-making processes do in fact make perfect sense.

Drawing on the extensive work in EP since it broke loose from sociobiology decades ago, a central theme in this book is that our default emotional and behavioral tendencies were well-honed to our best advantage in our deep past, where our species sprouted from in its “environment of evolutionary adaptedness” (known as the EEA in evolutionary-psychology circles).  Over hundreds of thousands of years of life in which social dynamics changed slowly and survival demands (food, shelter, protection, procreation, etc.) were predictable despite natural disasters and changes in climate, we have evolved highly successful behavioral patterns and strategies to meet these sorts of challenges.

Many of these evolved strategies still work just fine, but others don’t fit so well into our technologically-advanced, socially-complex world, which presents new and ever more daunting challenges to our innate behavior and our decision-making capabilities.  Still, the essential motivations and needs that drive our behaviors today remain relevant and pressing, and the decisions we make aren’t capricious, say the authors, but are largely rational when seen from this evolutionary perspective.

How does this decision-making process work in humans, exactly?  How different are we from other species?  We all acknowledge that animals use their innate adaptive capacities reasonably (though the term rational obviously wouldn’t apply). To this question the authors claim that nature has given humans not just one mind, but a handy toolkit of mental modules, each meant for its own special application – mating, gaining and maintaining group status and so on.  That is, although in our own experience each of us has a coherent identity of a single self, Kenrick and Griskevicius assert that this self is actually an evolved set of social-behavioral, emotional, cognitive and behavioral tendencies, and that our behaviors are actually orchestrated by seven distinct subselves.  “Instead of having just one self, we are really a collection of selves – – a group of subselves.  Like different personalities, each of your subselves has peculiar quirks and preferences.” 

Further, “Different subselves are activated in different social situations.” Each subself has its own principle domain, and when it is called on by the group (of subselves) to handle a particular situation, the collective-self defers, more or less automatically, to the expert subself to lead the way. 

The seven subself domains of expertise are (1) Self-protection, (2) Disease-avoidance, (3) Affiliation, (4) Status, (5) Mate-acquisition, (6) Mate retention, and (7) Kincare.  The labels given to these subselves are descriptive of their roles and areas of expertise, and the authors provide lots of entertaining illustrations, both of how these can work independently as well as how behaviors produced by one subself can appear wholly contradictory to those of other subselves.  For example, someone known for high ideals and strong ethics may nonetheless be caught having an extramarital affair: here is incongruence resulting from the presumably-rational motivations of different subselves.  Teens take great physical risks in the attempts to attract potential mates.  Some well-known Hollywood personalities live luxurious lifestyles while driving environmentally-friendly cars.  A rap singer raised in semi-poverty becomes wealthy but quickly squanders it all.  Are all these “decisions” irrational?  Only if one insists on a unified-self perspective, in which a conscious “me” makes all the decisions.

In addition to the solid evolutionary-psychology angle, the authors present findings from the relatively new field of behavioral economics.  Research in this area (and its related fields such as cognitive economics) has turned up oddities in human decision-making that appear to contradict what would be expected by standard economic theory.  Many of these anomalies are well known in the literature. 

For example, in both experimental settings and in real life, humans tend to be loss-averse in situations where an objective analysis and a mathematical odds-calculation would call for a riskier approach.  “Loss aversion is one of those things that led to a lot of head scratching among rational economists, the sharply dressed number crunchers. From the classic rational perspective, loss aversion is mathematically irrational….” 

But recognizing that an individual isn’t just a single, consistent and unified self helps us understand what’s happening here.  “Predicting whether a person will be loss averse or not [in a particular situation] requires knowing which of the seven people [subselves] in his or her head is currently at the controls.”

The notion that we are made up of multiple selves goes back a long way, of course.  For example, a quarter century ago, Robert Ornstein’s 1986 book, Multimind, portrayed the mind as a “hybrid system” in which various generally unconscious subsystems call the shots, while the conscious part of the mind takes credit (or blame) for our thoughts, behaviors and decisions.

In addition, the relatively modern notion that many or most of our decisions are the result of unconscious processes (generally outside conscious control) was perhaps of Freudian origin, but following on a flurry of research studies in the 1990s and on into the present decade, it is a belief now widespread among psychologists.  For earlier perspectives see for example the recently deceased Daniel Wegner’s The Illusion of Conscious Will(2002), or Timothy Wilson’s Strangers to Ourselves (also 2002, andmy review from 2003). More recent books include Eagleman’s Incognito: The Secret Lives of the Brain (2011) and Subliminal: How Your Unconscious Mind Rules Your Behavior by Leonard Mlodinow (2012).

And Robert Cialdini’s groundbreaking book, Influence (1984), laid some of the groundwork for behavioral economics with many instances of the strange and seemingly-irrational nature of human behaviors and social interactions.

This current book is both a good synthesis and an extension of all these earlier works.  And the ideas and instructive illustrations in this book are solidly grounded in the authors’ seven-subself model, which will perhaps lead the reader to reflect even further on these important ideas.  For example, how can we best make sense of human motivations that don’t fit so neatly into the domains of these seven subselves? What to make of intellectual curiosity, artistic expression, passion to discover scientific truths, and the like?  In what direction should our evolved nature best continue to evolve?

© 2014 Keith Harris

Keith Harris, Ph.D., is Chief of Research for the Department of Behavioral Health in San Bernardino County, California. His current interests include the empirical basis for mental health research, behavioral genetics, and the shaping of human nature by evolutionary forces.