Hi my DS is 3yrs 7 months and I think he may be behind in his social development. He barely speaks to his teachers or other kids at his preschool and when I go to relatives houses he will not initiate conversation with anyone and mostly ignores people! Even his nan and granda that he sees all the time? He does however like jumping all over them and making strange noises and flapping his hands in their faces!? Could this be a sign of something more? His speech is a bit delayed but he can talk to immediate family and is 75% understandable