As argued above in Section 3.2, scientists tend to focus on the environment - natural scientists (physicists, biologists, etc.) on the ecosphere, social scientists (economists, political scientists, etc.) on the sociosphere, and experts on the "sciences of the artificial" (architects, engineers, etc.) on the technosphere. Few focus on the person in the centre. The last thing we study is ourselves. There seems to be an unspoken assumption that there is no such thing as "human nature". There is, however, a huge body of empirical evidence about the nature of the person, which could be considered as a synthesis of the behaviouristic thesis and the humanistic antithesis.

Behaviourists are viewed as environmentalists and humanists as geneticists. That is, whereas the former tend to view the person as determined by the outside-in influence of the environment, the latter tend to view the person as determined by the inside-out unfolding of the genetic potential.

Introductory textbooks in psychology (including my own) intone, time after pompous time, that this or that behaviour is determined by some complex interaction between environmental and genetic factors.¹³ However, there seems to be a third factor. Once again, an anecdote may help:¹⁴

Chang and Eng were Siamese twins. Whereas Chang was practically teetotal and celibate, Eng was an alcoholic and a womanizer. Here were two people, who were genetically identical and had as close to similar environmental influence as possible, yet had totally different personalities. Their different personalities could not be attributed then to genetic factors, or environmental factors, or whatever complex interaction between them. There must be a third factor. Eng chose to lead the short happy life, whereas Chang tried for the long miserable one. Alas, poor Chang had to die when Eng died. However, most of us are not attached to another person and lead lives determined by our choices.

This does not imply that genetic factors are unimportant. Choice is a function of the natural unfolding of the potential of our species. Both phylogenetic (animal to human) and ontogenetic (child to adult) development could be best described - if they must be described in one sentence - as the progressive emancipation of the organism from the tyranny of the environment.

Nor does this mean that the environment is unimportant. There is no evidence that any group of people has cornered the market on any of the human vices or virtues. Different cultures create different climates which encourage or discourage different choices.

What is truly important, however, is the third factor of human choice. We are indeed constrained by our genetics and by our environments but, within those constraints, we can exercise choices to determine, to some extent, the course of our lives. We can write our own scripts.