The biologists have given us some idea of the kind of physiological equipment man is born with and the psychologists have made some progress in the description of the psychological equipment, all of which is no doubt familiar to the well-educated. On the other hand, the development of anthropology has been so rapid and the points of view so illy formulated that a few remarks as to the character of culture seem necessary. On one point all students are agreed, viz.: that it is the functioning of the psychic part of man that produces culture. When it comes to assigning cultural phenomena to specific psychic activities there is some difference of opinion, but for the most part it is recognized that since culture is not inherited it must be a construct and as such is largely the work of the intelligence. For a long time many psychologists and sociologists have seen in this distinction one of their most important problems. To them it appears that social progress or cultural change of any kind is in last analysis the production or creation of something by the psychic activities of individuals, which process has been regarded as invention. In practical life we are accustomed to apply this term to ingenious mechanical devices, but in fact anything produced by our psychic activities, whether it be a new game, a word, a picture, a song, etc., is the same kind of thing and one to which the term may be applied. Any such invention taken up by a social group of people becomes thereby a trait of culture.
Culture as anthropologists use that term is a complex of elements as varied as those making up our own lives. Most geographers, however, give their attention almost exclusively to the economic aspects of culture, or to those traits listed in anthropological literature under the head of material culture. This, no doubt, comes about because it is in these phases of life that culture and geography are in most direct contact; language, religion, literature, art, family organization, etc., are less articulated with geographical phenomena, but geographers are quite given to sweeping them all into the economic category and claiming the most intimate contact throughout. It is clear, however, that the primary problem is to be found in the relation between man's material culture and the earth, which for convenience we shall designate as the environment. Our question then becomes as to what kind of a relation exists between material traits and environmental characters.
Material traits, such as methods of preparing food, the manufacture and use of tools, the methods of the chase, weaving, pottery, etc., are clearly inventions, and if the environment has anything like a determining or a causal role in the making of culture, such must be manifest in the inventive processes themselves. Our problem here is complicated by the existence of two stages or steps. In the first place some individual must develop the idea and demonstrate it; then it must be taken up by others and become more or less common to the social group. The
