If your child is large for his age, it is not uncommon for others around him to treat him as an older child who is more emotionally more developed
Yes I think there IS some of that.
We speculate that her mind is ahead of what her body can do and that just angers her when she runs into that wall (having an older brother seems to fuel her drive to catch up to what he can do, and cause rage when he can do things she can not do yet).
You know what...This is an interesting idea. My husband has a very high IQ and my mom is mentally ill but is also on a very high intellectual level. I'm not a stupid person myself, but I'm used to living with people who are smarter than I am. My husband and my mom have always had problems conceding my points because deep down they see errors in whatever my argument is. Maybe my son is doing this too, but it's coupled with the strong toddler emotions. So he's not able to take the next step that we adults do where we swallow our pride and say "okay" when secretly we think the other person is still wrong.
