Their genetically determined modes of behavior, which are the same in all members of a given species, constitute the properties of their specific nature. But it is maintained also that members of the human species do not have genetically determined behavioral dispositions that can be regarded as properties of a specific human nature. Those who hold this view are quite correct in thinking that genetically determined human nature is different from the genetical determined specific natures of other animals. In a global investigation, one would find that the behavioral dispositions of human beings are as varied as the places where we find human beings in action. The reason is that specific human nature is constituted only by the possession at birth of the same potentialities for behavior rather than, as in other animals, the same actual behavioral dispositions.
Potentialities are capable of a wide rage of actualization.
Take, for example, the capacity that all human beings have for acquiring language, think of the innumerable languages that human beings do, in fact, acquire. That infant shares with every other infant regardless of biological paternity, the same behavioral potentialities that can be actualized differently when the child is reared in a household that is a different from the family in which it was born. One property of specific human nature is the potentiality for learning to speak a human language. The language that the child learns to speak is determined not by its specific nature, but by the way in which it is nurtured. It is nurture that determines the different actualization of all the potentialities that constitute specific human nature.