Adamantium wrote:
My understanding is that this classification system has no basis in reality.
The underlying thinking has been debunked.
People still use these terms because they seem more sciencey than "fat, skinny, muscular" but they don't really mean anything and for some people they suggest some sort of biological destiny which is baseless.
Actually, they're decent as physical classifications.
But what's debunked is the idea that they have any link with your personality. About the only 'body shape = personality' link that has any data is that mesomorphs are slightly more likely to be aggressive, and that's just because they can get away with it.