Even though serial killers like Ted Bundy looked and acted "normal" on the inside, he wasn't. I find it very difficult to define normal behavior, due to the large variations in what is “normal”. Our society accepts many forms of normal behavior, whether it is an issue of gender identity or being LBGT, both of which would never have occurred or been accepted in 1970. Thankfully, we live in a country and we have information that challenges our children and our children. to ensure they are reaching “normal” developmental milestones. Absence of language by a certain age is a milestone used to test a child for autism (Hooley, Butcher, & Mineka,