When my 19 month old son gets really excited about something he shakes his hands. For example if he's watching his favourite cartoon. It's not something he does all the time. Someone worried me saying this could be a sign of autism but I think he is just trying to express his excitement. Does anyone elses little ones do this? Socially he interacts well, has good eye contact, answers to his name, does not have a strict routine, has a small vocab but think that's expected for his age group.