Human beings are hard wired to seek pleasure and avoid pain. It may not be actual pleasure and pain. It can be imagined potential pleasure or pain. Further, the pleasure and pain need not be limited to physical. It can also be mental or emotional pain.

We love whatever that give us pleasure - physical, mental and emotional; be it actual or imagined. Likewise we hate whatever that gives us pain - physical, mental and emotional and whether actual or imagined. Some people even hate others when they are put to mere physical, mental or emotional discomfort by the other.

People who believe themselves to be superior, would be unhappy if a supposedly inferior person is given equal recognizance and rights (for example, citizenship rights or college admission) or performs better than him/her and is more successful than him/her. The superiority complex causes the person to suffer pain, discomfort or unhappiness in such circumstances.

Hatred does more damage to the hater than the hated. See The Destructive Power of Hate