Adolescents are much more likely than other age groups to engage in risky behavior such as aggression, crime, promiscuity, reckless driving, and drug use. It is tempting to consider these behaviors as maladaptive or pathological. But much of what we consider pathological is in fact adaptive in the evolutionary sense of the word. That’s a subtle but essential point to make about evolutionary thinking in general. A metaphor I adopt is that the human behavioral system can be thought of as like the immune system, with an adaptive component and an innate component. The innate component is a psychological and physiological architecture that evolved by genetic evolution and would be much the same in humans as in other mammals. We could also call this closed phenotypic plasticity. The adaptive component is more open-ended and represented by Skinnerian processes: things like operant conditioning, and also language as studied in Contextual Behavioral Science with relational frame theory and by authors such as Eva Jablonka and Marion Lamb in their book Evolution in Four Dimensions.

Against this background, evolutionist Bruce Ellis emphasizes the innate component of the human behavioral system, much like in other mammals, while behavioral scientists Joseph Ciarrochi and Louise Hayes concentrate on the adaptive component of the behavioral system, having much to do with selection by consequences and its extensions into symbolic thought and language. These positions do not initially seem to have any overlap, and yet there may be a way to usefully integrate the two perspectives.

Much of this conversation is based on the premise: “Change the context and individuals (or groups) will adapt to that context,” as if the process of adaptation is straightforward. But actually, it’s not straightforward, or at least sometimes it’s not. Even to change in the direction that everyone wants to change will still require some kind of work. That’s one place where Acceptance and Commitment Therapy (ACT) comes in, to accomplish that kind of work through things that are familiar to the ACT community — such as changing psychological flexibility, perspective-taking, or working around obstacles. It’s a process that needs to be managed because our natural learning abilities, in true evolutionary style, just climb a local peak and are not capable of traversing a multipeak adaptive landscape.