The emotions of humans are more complex than those of other animals. this is to be expected since human mental capacity is greater.
We often talk about controlling emotions through logic, or about the logic mind being better than the emotional mind. This is rubbish. Logic, in itself, is useless. Logic is simply a tool to solve problems. Our brains use logic to solve problems too - achieving our emotional desires - whether that emotional desire is to rule the world, to win the Nobel prize, to have many children, or to get beaten up by a drunken partner every Saturday night. Of course our emotional desires are insatiable so the task is never complete.
The main emotions are
and arguably
We also see fear of death - a useful mechanism because it kept humans alive for longer than they otherwise would be. Clearly a population which had no fear of death, and was in the habit of committing suicide whenever mild depression set in would not go forward and populate the earth.
Depression is a mechanism for replaying events over, so that a bad situation can be analysed and so that similar situations can be avoided in the future.
There is a tension between rationality and emotion. Rationality is about achieving long term goals (even long term emotional goals), whereas emotional drives are immediate. Punching that rude policeman's face in may seem like a very attractive proposition right now, but logic suggests that longer term this will not increase your emotional well being. The irrational person acts, the rational one resists, and the rational one ends up satisfying more of their emotional desires in the longer term. The rational one is no less emotional than the irrational one, just more rational.
See