There is no supernatural explanation for why we humans feel compelled to help people we do not know. Even when helping others gives us no immediately competitive advantage, according to Dawkins’ selfish gene theory, we do gain from acts which appear selfless, in the long run, because natural selection favours individuals who can show compassion and restraint.
We can identify with the needs of others because we can see ourselves in their place and what we would like to have done to us in their place; the golden rule. Do to others what you would have them do to you.
Compassion is a particularly strong emotion when we see need in the young of other living creatures, but this is not unique to Homo sapiens as this incredible footage shows, when a Leopard almost seems to regret killing a baboon.