Humans

Humans AKA People biengs are, well you. Humans are descended from Australopithecus. Some think humans evolved intelligence because they had no other strategy for surviving, but that is debunked by the human adaptation to long distance running.

Some think humans have an unique ability to be cruel, but that is debunked by the fact that if proto-humans punished the more intelligent human-like individuals while applying "cannot help it defence" to more primitive individuals, that would selectively have bred against human-like characteristics and humans would not ever have evolved.