Brainsâ€™ Social Network Formula Hundreds of Millions of Years Old
A new neural analysis suggests that our social networking tendencies most likely have their neural roots in some of our early vertebrate ancestors. The findings were published online in the journal Science.
â€œThere is ancient circuitry that appears to be involved in social behavior across all vertebrates,â€ Hans Hofmann, an associate professor of integrative biology at the University of Texas at Austin and co-author of the new study, said in a prepared statement. Judging from the evolutionary family tree, Hofman observes, these conserved neural clusters originated at least 450 million years ago. The researchers examined two parts of vertebrate brains: the so-called â€œsocial behavior network,â€ which also includes hormones for social and sexual behavior, and the â€œmesolimbic reward system,â€ which is involved in dopamine signaling that activates when we engage in pleasurable behavior. Together these two areas make up the social decision-making network, which helps humans, rainbow trout and wild boars know when to flirt or fight or form a posse. They found impressive similarities in the brains of all 88 vertebrates they studied, which included mammals, reptiles, birds, amphibians and teleost fish.