Body doubles

I saw film Analyze this yesterday (*God knows which time) and it crossed my mind that I so often watch body doubles instead of actors.
Namely, there were many close-ups in which Billy Crystal was hugging with De Niro and his fellow mobsters.

An I notice that De Niro had extremely ugly hair cut from behind. Plus that hair was dyed. The neck was ugly.

It was a body double, I thought. Then, on IMDB there was none listed as body double or at least stand-in for De Niro.

He could have had better haircut then.

Still, never trust the person from behind on wide screen...

Why use a body double if it's not a bare buttocks scene?

Originally posted by Seitse
Why use a body double if it's not a bare buttocks scene?

Originally posted by FreakyKBH
Side note: I was asked to be a body double for a scene in [b]"Boogie Nights," but modestly declined...[/b]

Originally posted by Seitse
Why use a body double if it's not a bare buttocks scene?