David Sloan Wilson and Steven C. Hayes, briefly describe why a dialogue between Evolutionary Science (ES) and Contextual Behavioral Science (CBS) is timely and needed. They explain that this book seeks to integrate two bodies of knowledge that have developed largely independently during the last half-century. ES already provides a unifying theoretical framework for the biological sciences and is increasingly being applied to the human-related sciences. CBS is a modern face of functional and contextual views of psychology that developed around learning theorists such as B. F. Skinner, and that trace themselves back to the functional views of pioneers such as William James and John Dewey. CBS seeks to understand the history and function of human behavior in the context of everyday life, where behaviors actually occur, and also to influence behavior in a practical sense. These differences, as the editors discuss, establish a degree of dynamic tension that this volume discusses about where application fits in ES.

In this dialogue, behavioral scientists Michael J. Dougher and Derek A. Hamilton, discuss their view of how to establish a more contextual science of learning by integrating CBS and ES perspectives, while evolutionist Eva Jablonka explores whether ES suggests a different division among types of learning. The discussion is far-ranging, addressing such issues as the nature of learning itself, how it can be defined, how to address issues of retention and memory, and the criteria that should be used to consider types of learning.

Behavioral scientists Dermot Barnes-Holmes, Yvonne Barnes-Holmes, and Ciara McEnteggart, discuss the behavior-analytic approach to human symbolic thought and communication, and its evolution, as viewed predominantly through the lens of relational frame theory. In contrast, evolutionary anthropologist Terrence Deacon argues that the conventionality of language is itself a reflection of these iconic and indexical relations re-emerging in the form of relations between symbols.

Evolutionist Bruce Ellis discusses how natural selection shaped the adolescent brain to respond to environmental opportunities and challenges. This helps to explain why adolescents engage in risk-taking behaviors. Behavioral scientists Joseph Ciarrochi and Louise Hayes argue that a contextual behavioral science approach can unify the different fields of research in the service of facilitating positive youth development.

Behavioral scientists Kibby McMahon and M. Zachary Rosenthal discuss how emotional expressions are accurately recognized from the perspective of a model known as “contextualism,” while evolutionists Lynn O’Connor and Jack Berry adopt a universalist interpretation and argue that emotions evolved as part of the highly complex mental apparatus of the mammalian brain, exquisitely designed and organized for nursing babies who come into the world entirely dependent upon their mother.

Evolutionists J.W. Stoelhorst and Mark van Vugt discuss how evolutionary theory can help managers guide organization development through the recognition that firms are best understood as historically and culturally specific solutions to the problem of achieving and sustaining large-scale cooperation among genetic strangers. Behavioral scientist Frank Bond discusses how psychological flexibility is a primary determinant of mental health and behavioral effectiveness that leads to a contextual behavioral interpretation.

In this dialogue, evolutionary psychologist Aaron Blaisdell discusses how “evolutionary mismatch” is the best framework for understanding human health and disease in the modern world, while behavioral scientist Kelly Wilson suggests modern health is a product of contextual behavior: For millennia, humans died from what the world did to us. Humans have conquered an astonishing array of these hardships. But the conquests have come at a cost.

Evolutionist David Sloan Wilson discusses how, within the context of evolutionary theory, small groups emerge as a fundamental unit of human social organization, essential for human well-being at both smaller and larger scales. Along with behavioral scientist Paul Atkins, the two suggest that Prosocial is a strategy for uniting the evolutionary and contextual behavioral science perspectives.

Evolutionists Steven Hayes and Jean-Louis Monestes discuss psychological inflexibility and how this is accounted for with variation and selection, while behavioral scientist Renee Duckworth discusses how neuroendocrine mechanisms suggest that stable differences in behavior among individuals are underlain by structural variation in neuroendocrine components, and this relatively inflexible scaffold is needed to enable more flexible components to function.

Evolutionary biology is richly contextual. You can’t understand any species except in relation to its environment. As such, contextualism is baked into the DNA of evolutionary biology, but mostly with respect to genetic evolution. Contextual behavioral science emphasizes context, but mostly with respect to behavioral flexibility, not genetic evolution. In this way, both fields are contextual in their own way, but at different scales.