My name is Benjamin Zubaly. I am an incoming PhD student in the Evolutionary Social Psychology lab at the University of Michigan and a research assistant in the Ayers Psychology and Evolution (APE) lab at Boise State University. I joined the APE lab to study the psychology of friendship from an evolutionary perspective. But why would an evolutionary psychology lab be so interested in friendship? Our friendships are incredibly important to us, taking up much of our time and effort and providing some of the most intimate and meaningful human connections in our lives. It is obvious that friendship is worth studying. But what could evolution have to do with the complexities of friendship? Isn’t evolution only relevant to more basic instincts, like hunger and fear? To answer these questions, we must consider the challenges that our ancestors faced over deep time.
The fundamental insight of evolutionary psychology is that the mind exists to produce behavior that facilitated survival and reproduction in our species’ past. We are all descendants of an unbroken chain of ancestors—back to the first biological organism—all of whom survived long enough to reproduce. In contrast, untold numbers of organisms failed this task, removing their genes and thus their psychological designs from existence. This filtering mechanism, natural selection, produced minds that are designed to guide our bodies in unbelievably sophisticated ways towards survival and reproduction.
Initially, it is not clear how friendship relates to survival and reproduction. Seemingly basic psychological mechanisms like fear obviously have survival value. Fear allows you to avoid predators and death directly. Thus, fear is a psychological adaptation, meaning it is a part of the mind that was shaped by natural selection to improve fitness. But having a psychology that manages friendship is not life or death, right?
Our ancestors’ minds were honed in the environment of evolutionary adaptedness (EEA), which is the composite of all the environmental features that regularly influenced our survival and reproduction. These features can be thought of as adaptive problems to be solved by the mind in order to reproduce, and to be important, these problems must have existed with us throughout deep time. Many such adaptive problems exist, such as predation. Similarly, social adaptive problems have existed ever since animals lived in groups. For example, there is the problem of reciprocal altruism (Trivers, 1971). That is, being altruistic towards others is more costly than beneficial—unless the altruism is reciprocated. There is also the problem of alliance formation (DeScioli & Kurzban, 2009). In our past, having a group to rely on would be tremendously beneficial in warfare, hunting, and collective problem solving. Additionally, there is the problem of communal sharing (Winterhalder, 1986). Giving away resources such as food is disadvantageous, but if resources come in large amounts and on rare occasions, then sharing is necessary for everyone to consistently have enough.
Each of these adaptive problems—and presumably many others—can be solved through friendship. Having friends gives you reciprocation partners, a group to rely on, and a community to distribute resources within. Evolutionary logic tells us that we should have a psychology that causes us to make friends, keep them when they help us solve these problems, and lose them when they don’t. Like fear, friendship would have facilitated survival and reproduction. This is why the APE lab uses evolution to understand the psychology of friendship, and it highlights why I find an evolutionary approach to the mind to be so fascinating and illuminative.
It is tempting to assume that, apart from “basic” psychological processes like fear and hunger, most meaningful aspects of our lives are immune from evolutionary influence. This view is misled, because even seemingly complex and sophisticated social processes like friendship thoroughly rely on our evolved psychology. By understanding the intricate social adaptive problems that humans faced in the evolutionary environment, we can better understand both how and why the mind works the way it does.
References
DeScioli, P., & Kurzban, R. (2009). The Alliance Hypothesis for Human Friendship. PLoS ONE, 4(6), e5802. https://doi.org/10.1371/journal.pone.0005802
Trivers, R. L. (1971). The Evolution of Reciprocal Altruism. The Quarterly Review of Biology, 46(1), 35–57. https://doi.org/10.1086/406755
Winterhalder, B. (1986). Diet choice, risk, and food sharing in a stochastic environment. Journal of Anthropological Archaeology, 5(4), 369–392. https://doi.org/10.1016/0278-4165(86)90017-6
