First, it is clear that our species' common genetic heritage confronts the mmebers of every society with the same basic physical needs.  These include needs--for food, water, sleep, warmth, and oxygen--that must be satisfied if we are merely to survive.  In additions, there are a variety of other needs that vary in intensity from individual to indivicual, and from stage to sage within an individual's life.  Among these are sexual needs, and the need for play, the need for new experience, and the need for socia experience, all of whcih have been shown to have a genetic basis (1991, p. 23).

Second, humans everywhere develop a variety of derivative needs and desires that reflect their social and cultural experiences as well as their genetic heritage.  Because these experiences vary from society to society and among individuals within the same society, the nature and intensity of the needs also vary (1991, p. 23).

Third, the members of every society have the same basic physiological resources to use in satisfying their needs (1991, p. 23).

Fourth, humans are all dependent on the societal mode of life, especially during the formative years (1991, p. 24).

Fifth, as we have already seen, we humans have an immense capacity for learning and for modifying our behavior in response to what we learn (1991, p. 24).

Sixth, humans everywhere have the capacity to create and use symbols systems and cultures (1991, p. 25).

Seventh, humans have a highly developed awareness of self and an acute consciousness of their situation with respect to the rest of the world (1991, p. 25).

Eighth, our species'heritage includes powerful emotions and appetites inherited form remote prehuman ancestors (1991, p. 25).

Ninth, and finally, humans are powerfully motivated to put their own needs and desires ahead of those of others, especially when the stakes are high (1991, p. 25).