The inhuman origins of culture : the role of ecological relatedness and density

What do ground squirrels, killifish, and humans have in common? The answer is that all have evolved to adopt certain traits and behaviors, in response to variation in environmental and ecological conditions. This is known as adaptive plasticity. I outline how thinking about adaptive plasticity, and animal behavioral ecology more broadly, can provide novel insights to our understanding of the nature and origins of human cultural variation. Specifically, I focus on two lines of work: (1) the psychological effects of living in environments where individuals are surrounded by many family relatives-referred to as ecological relatedness, and (2) the psychological effects of living in environments with many unrelated individuals (i.e., high population densities in general). I highlight how this perspective can generate novel predictions about cultural variation and also integrate existing cultural psychological explanations. Finally, I discuss how this perspective is similar to or different from existing theoretical perspectives, and key questions that remain.