Drinking alcohol and eating snacks are far and away the most transmittable food behaviors, the longitudinal study finds. In fact, they’re the only food categories in which friends influence one another’s eating habits. Spouses, meanwhile, transmit these eating habits alongside many others: being healthier, avoiding caffeine, and consuming meat and soda. Brothers stand out as the only social relationship studied in which alcohol consumption wasn’t transmitted, but meat-eating was. For sisters, just alcohol and snacks came up as socially transmissible eating habits.  

What’s with the high likelihood of drinking being passed through our social networks? It matches up nicely with the social relationships that surround how and where we eat. “The rather consistent emergence of  ‘alcohol and snacks’ as a concordant pattern across relationship types harmonizes with the intuition that this form of consumption is also intrinsically more social in nature. Items in this food pattern are easy to share and often require less of a time commitment relative to meals,” researchers Mark Pachucki, Paul Jacques and Nicholas Christakis write. “In addition, in American society, alcohol is culturally associated with sociability.”