Drooling for Drama

Are our kids doing a spit take?

This is Sandra Tsing Loh with the Loh Down on Science.

Would you share a soda straw with a stranger? How about your sister? Family bonding sometimes means swapping a little spit!

Ashley Thomas and colleagues from Harvard University wondered – can BABIES tell the difference? They used cartoons and puppets to act out social scenarios to a group of toddlers and infants. Their experiments tested if babies are able to identify human bonds and predict future behavior.

Turns out, the secret is … SALIVA! Actors either mimed playing ball, or sharing orange slices together. When an actor then seemed upset, the children watched them MORE closely if they had shared the orange – in other words, swapped spit!

Why? The researcher believe the kids seemed to expect BONDED individuals to care more about each others’ emotions.

They suggest infants watch simple behaviors, like saliva sharing, to identify closeness between people! The babies use this information to predict behaviors and learn how family groups work.  

Even babies are drooling over the latest drama!

Reference: Thomas, A. J., Woo, B., Nettle, D., Spelke, E., & Saxe, R. (2022). Early concepts of intimacy: Young humans use saliva sharing to infer close relationships. Science, 375(6578), 311–315. https://doi.org/10.1126/science.abh1054