Most 2-year olds are assholes simply because they don't really have a full social and mental conception of the world around them. They struggle to understand others feelings in many cases and the consequences of their actions. It's a big difference whether someone doesn't realize what they're doing is painful and wrong, versus someone simply not caring. I imagine he's seen people playing with dolls, and you'd never treat a baby the way many little kids treat dolls, etc. Correct him strongly, and keep a very close eye. Kids that age shouldn't be left unsupervised together, if nothing else due to risk of accidental injury to the baby. If there are issues, get him help early when it will make the most difference and don't assume it's something he can't change. His personality is still quite moldable at this point.

Empathy needs to be repeatedly modeled and encouraged in toddlers before it becomes a part of their behavior. Seriously tho, writing your child off as a psychopath will almost guarantee that they become one in the future.