Monkeys that spend a lot of time alone exhibit autistic-like traits, diminished social motivation, and reduced grooming.

“if you look at monkeys that spend a lot of time alone they have a much greater burden of autistic like traits measuring on this rating scale they have diminished social motivations so other monkeys will come up and interact with them but they don't engage in um social overtures them that much themselves they do less grooming less uh affiliative um behaviors”