Lately I've come up against the same situation over and over with my son, kids in my primary class and my nephew. What's the issue, you ask? Well, all these kids physically appear to be normal. However developmentally, they are not.
My nephew was adopted from Haiti about 8 years ago and came here with some pretty significant health issues. Due to these health issues, he is developmentally delayed. So even though he appears to be physically 11, developmentally he is 6. An Adults expectation's of a 6 year old vs an 11 year old differ quite a bit.
I've seen this with my own son as well. He looks and acts very normal most of the time. So when he gets upset and throws a fit, it can be rather shocking for others. My family is great with Jackson, but when this happens, they freeze up and don't know what to do. What I try to remind them is that he is a couple years behind in some areas. In a few ways, he's like a 5-6 year old.
What I want people to get from this, is to try and remember to have patience for kids with developmental disabilities. They most likely look and act "normal" but keep in mind, they are not. Their brains function differently and at different levels too.