Altruism is best described as behaving unselfishly to enhance the welfare of others. exerting greater effort when working in the presence of others. experiencing an increasing attraction to people as they become more familiar.

It is behaving unselfishly to enhance the welfare of others. For example: studies show that blue whales often exhibit altruistic behavior; putting themselves in danger to defend the lives of other creatures (even creatures outside of their species) when they are being attacked, or in trouble.