Editor’s Note: Dario Maestripieri is professor of comparative human development, evolutionary biology, neurobiology, and psychiatry and behavioral neuroscience at the University of Chicago. He is the author of "Games Primates Play: An Undercover Investigation of the Evolution and Economics of Human Relationships."
What can biology tell us about human behavior? This question can be answered in many different ways depending on what we mean by biology and what aspect of human behavior we are interested in. For example, in my recent book "Games Primates Play: An Undercover Investigation of the Evolution and Economics of Human Relationships," I discuss how our evolutionary history, our genes and our close relatedness to other species of primates can explain the way we behave in our social relationships with our relatives and friends, with business and romantic partners, and even with a stranger we’ve just met in an elevator.
On April 3, the day of the Republican primaries in Wisconsin and Maryland, I was interviewed on a radio show in Chicago and asked what biology can tell us about the behavior of the candidates for the next presidential elections. The theme of the show was “trust,” always an important issue in politics. When politicians run for office, they make promises to people about what they will do when they are elected. The problem for us, the people, is to try to predict whether the politicians will actually do what they say they will do. Trust is about trying to predict the future, and that’s not a trivial problem. Are politicians truthful when they make promises in a campaign speech, or do they lie? How can we tell?
It’s been suggested that when people lie, their anxiety and fear of getting caught makes their lies “leak” through their nonverbal behavior. For example, when people are lying to someone, they might avoid direct eye contact with this person or show signs of nervousness, such as scratching their heads or playing with their keychain. People who are highly trained to give verbal performances in front of audiences, such as actors or politicians, however, have learned to make eye contact with others and to suppress any fidgeting. So, if they lie, they don’t give it away with these signs. But, as I told the host of the radio show, even the bodies of the best liars give away some clues as to what their minds are actually thinking.