Atheists, secularists and the intellectually curious gathered in The Grove on Chapel Street Sunday afternoon to hear Yale psychology professor and Head of Silliman College Laurie Santos discuss the scientific reasons why humans imitate the destructive behavior of others.

The event, titled “How to Think Different,” was part of a “How to be Human” lecture series sponsored by the Yale Humanist Community, a group of Yale students and New Haven residents with common interests in atheism and secularism. In her talk, Santos explored what she said is a distinctively human trait: copying the habits of one’s peers.

“The minds of humans are sponges for other people’s ideas,” Santos said. “Being a species that wants to share makes us a species who connects positively, but also makes us a species that is especially prone to the negative ideas of others.”

To illustrate her point, Santos presented a series of slides and short videos that demonstrated the human habit of sharing ideas and thoughts with others. She contrasted the behavior of chimpanzees with human children in order to demonstrate that only humans are able to share ideas with one another. For example, while both toddlers and chimpanzees point at objects they desire, a phenomenon known as “proto-imperative pointing,” only human toddlers point with the goal of attracting the attention of other people and sharing the experience.

In the modern era, this desire to share has led to inventions like Facebook and Wikipedia, which Santos said facilitate instantaneous sharing. But the need to share has spawned inventions throughout human history, she said.

Santos told the story of nineteenth-century inventor Henry Fox Talbot, who helped develop precursors to the first camera. Santos said Talbot’s invention arose out of his desire to share his honeymoon trip with his friends back home.

Audience members interviewed said Santos’ ta;l raised new questions about human behavior.

Ali Bandeali SOM ’18 said the lecture made him question the meaning of originality in the context of Santos’ main points. Bandeali said that in an age of constant idea sharing, being original takes on a different meaning.

“[Santos] provided the evidence in a clear and convincing manner,” Sarah Gannett ’20 said. “Though the presentation itself was short, I think the talk set the foundation for incredibly far-reaching conversations. People around me afterwards were discussing education, formal religion and other rituals, and Santos set the stage for these discussions.”

The human desire to transmit experiences is tied to our inclination to imitate the bad behavior we see in others, Santos argued. Another video contrasting toddlers and chimpanzees showed that human children are predisposed to copy others’ behavior, even if that behavior is against the children’s best interests.

Because human minds so easily absorb negative ideas from others, Santos urged her audience to be mindful of the quality of the information that they receive.

“Our filter for bad ideas is not as good as we expect,” Santos said.

In a question-and-answer period after her talk, Santos said that humans can pick up abstract ideas and rituals, either through religion or through culture, that detract from human flourishing.

These lessons are especially important to Yale students, Santos said, as undergraduates are particularly disposed to risky behavior.

“I also worry more about the assumptions that undergraduates have about the percentage of students doing bad behavior, such as drinking too much or having unprotected sex,” she said. “They always think that the percentage is higher than it is, so then they do it more, which perpetuates [the cycle].”

Santos is in her first year as the Head of Silliman College.