Altruism tells that Altruism is:-
the principle or practice of unselfish concern for or devotion to the welfare of others (opposed to egoism ).
behavior by an animal that may be to its disadvantage but that benefits others of its kind, as a warning cry that reveals the location of the caller to a predator.

These are reasonable explanations. The Wikipedia gives it an extra meaning; telling us that Altruism is a concern for others, compassion, the opposite of selfishness but distinguishes it from loyalty. If it becomes disloyalty; working against one's own then it is Pathological Altruism, acting against long term interests, against survival.

Being concerned for the family, clan tribe or nation is Enlightened Self-Interest or just Self-Interest; ultimately caring about the greater good of one's own is loyalty, indeed it is Patriotism. Recall what The Bible tells us at John 15:13 -

Greater love hath no man than this, that a man lay down his life for his friends.

It does not say that about his enemies or rivals.


Altruism ex Wiki
Altruism or selflessness is the principle or practice of concern for the welfare of others. It is a traditional virtue in many cultures and a core aspect of various religious traditions and secular worldviews, though the concept of "others" toward whom concern should be directed can vary among cultures and religions. Altruism or selflessness is the opposite of selfishness.

Altruism in biological organisms can be defined as an individual performing an action which is at a cost to themselves (e.g., pleasure and quality of life, time, probability of survival or reproduction), but benefits, either directly or indirectly, another third-party individual, without the expectation of reciprocity or compensation for that action.

Altruism can be distinguished from feelings of loyalty, in that whilst the latter is predicated upon social relationships, altruism does not consider relationships. Much debate exists as to whether "true" altruism is possible in human psychology. The theory of psychological egoism suggests that no act of sharing, helping or sacrificing can be described as truly altruistic, as the actor may receive an intrinsic reward in the form of personal gratification. The validity of this argument depends on whether intrinsic rewards qualify as "benefits."

The concept has a long history in philosophical and ethical thought. The term was originally coined in the 19th century by the founding sociologist and philosopher of science, Auguste Comte, and has become a major topic for psychologists (especially evolutionary psychology researchers), evolutionary biologists, and ethologists.