Here’s one from about 3 seconds of Googling: The importance of touch in development (2010) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2865952/ https://www.n

Here’s one from about 3 seconds of Googling: The importance of touch in development (2010) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2865952/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2865952/ It’s not human exclusive, and it’s woven into our chemical makeup. “In rats, the amount of maternal licking received as a pup has a profound impact on the behaviour and physiology of the adult.” Feel free to continue the search to answer your own question.