Are all people egoistic?
Psychological Egoism is a theory which has its roots in ancient Greece, has had many philosophers such as Hobbes subscribe to it, and has now to a certain extent permeated into the consciousness of society. However, few philosophers now accept its description of human behaviour, because of the many criticisms which can be levelled against it.
Psychological Egoism is a descriptive theory: it makes the claim that the aim of each and every person's action is the maximisation of their own welfare: all humans are purely self-interested. This is to be distinguished from ethical egoism, which states that every person ought to act in such a way as to maximise their own welfare; this has its own attendant problems. The only real argument for traditional psychological egoism is to move from the fact that we so often do see people acting solely out of self-interest and then to form a generalisation that all people act out of self-interest all the time. It would seem as if fairly simple counter-examples could prove psychological egoism to be false: a typical one is that of someone who gives money to charity, rather than spending it on herself. In this case, it seems obvious that she is sacrificing her own interests in order that others' interests may be satisfied. However, the advocate of psychological egoism would reinterpret the situation, and find some reason based on self-interest why she would give the money to charity: she would wish to impress her peers, perhaps, or she does so for the happiness that that gives her. The psychological egoist would argue that all such cases of apparent altruism boil down to self-interest. Psychological hedonism, that is, the theory that the end of all human action is the agent's own happiness or pleasure, is a form of psychological egoism, and has also been a popular claim, most notably among classical utilitarians such as Bentham or Mill. Frequently psychological egoism in the end boils down to psychological hedonism, as in the above example where the 'real,' motive for the charity-giver's action is the happiness it brings her.