Editor’s note: Brain Basics from Scientific American Mind is a series of short video primers on the brain and how we feel, think and act. Below is a synopsis of the sixth video in the series written by a guest on this blog, Roni Jacobson, a science journalist based in New York City.

By Roni Jacobson

Evolutionary psychologists attempt to explain human behavior through the lens of natural selection, a term coined by Charles Darwin in 1859 to mean that traits that enhance an individual’s survival prospects in a particular environment will be more likely to be passed on to subsequent generations. Those that don’t boost reproductive success, on the other hand, will eventually disappear from the population. Sometimes criticized for producing overly simplistic or untestable theories, evolutionary psychologists don’t claim to have all the answers, but insist that the framework of evolutionary psychology can be a useful guide when assessing why we act the way we do.

One of the classic puzzles in evolutionary psychology is altruism, the practice of doing nice things for others without expecting anything in return. At first blush, altruism seems detrimental to survival. Why put yourself at risk for another’s benefit? Altruistic behavior does seem to be hardwired in the brain, however; it has been observed across multiple species, including dolphins, dogs and rats. Evolutionary psychologists have come up with two main theories to explain the behavior: reciprocity and kin selection. In this video, Daniel Cervone, a professor of psychology at the University of Illinois at Chicago, describes how the possibility of future favors or benefits to relatives may motivate us to be kind to our fellow humans, even if it costs us in the short run.

Other Brain Basics videos:

Remember When...How Your Brain Builds A Memory

Terrified or Hopping Mad? What’s Going on Inside You

A Transformation of Light: How We See

Quick! What Is The Word for a Pair of Opposites?

The Hidden Power of Others Over You

Small image on blogs page: Courtesy of Donald Lee Pardue via Flickr.