Learning what's dangerous is costly, but social animals have a way of lowering the price

MAY 12, 2020

by Champalimaud Centre for the Unknown

What would you do if the person standing next to you suddenly screamed and ran away? Would you be able to carry on calmly with what you're doing, or would you panic? Unless you're James Bond, you're most likely to go for the second option: panic.

But now imagine another scenario: While out on the street, the person walking in front of you suddenly freezes—she stops moving and becomes perfectly still. What would you do?

"Here, the answer becomes more tricky," says Marta Moita, head of the Behavioral Neuroscience Lab at the Champalimaud Centre for the Unknown, in Lisbon, Portugal. "Even though freezing is one of the three basic instinctive defense behaviors [along with fight and flight], animals don't instinctively know that when others freeze, they are actually responding to a threat."

For social animals such as ourselves, being able to tell if a group member senses a threat can be a matter of life and death. How does this learning happen? To find an answer to this question, Moita and her team engaged in a series of studies. Their most recent findings are presented in two scientific articles, one that was published today (May 12th) in the journal PLOS Biology and another published a few months ago in Current Biology. Together, their results reveal a mechanism by which animals acquire fear of freezing and outline the neural circuitry that underlies the expression of that fear.

Continued