Saliva Sharing Might Help Kids Identify Their Closest Relationships

How do little kids understand who has a close relationship with them? One of the clues they use to figure it out is by noticing who they’re swapping saliva with. The closest bonds are with the people who are giving them kisses, sharing their forks, and wiping their drool. Those are the findings of a recent study published in the journal Science.

Ira is joined by Ashley Thomas, the study’s lead author and a post doctoral fellow in the brain and cognitive sciences department at the Massachusetts Institute of Technology, in Cambridge, Massachusetts.