Again, either through a change in climate or through the improvement of trade, a food that was scarce may become plentiful. Or a people may remove to a new habitat, different from that in which their customs of eating were formed. If environment alone were the dominating cause of their customs, these customs should then immediately alter. As a fact, a group sometimes adheres to its old customs. The immediate cause of such conservatism is habit or inertia or inclination toward superstition or fear of taboo, all of which are mental reactions expressed in folkways or social customs. Thus environment remains at most a partial and indirectly operating cause.
A case in point is that of the Jews. It is often said that the Jew’s prohibition against eating pork and oysters and lobsters originated in hygienic considerations; that these were climatically unsafe foods for him in Palestine. This explanation is more simple than true. Ancient Palestine was an arid country in which hogs could not be raised with economic profit, and so they were not raised; and the Philistine and Phœnician kept the Jew from the coast along which he might have obtained shellfish. Eating neither food, he happened to acquire a distrust of them; having the distrust, he rationalized it by saying that it was foreign and wicked and irreligious to act counter to his habits—just like the Pueblo Indian; and in the end had the Lord issue the prohibition for him. Yet this outcome is a long way from the starting point of natural environment. The environment may indeed be said to have furnished the first occasion, but the determining causes of the taboos in the Mosaic law are of an entirely different kind—distrust, custom, rationalization, psychological or cultural factors. If doubt remains, it is dispelled by the orthodox Jew of to-day, whose environment thrusts some of his forbidden foods at him as economically and hygienically satisfactory, whereas he still shudders at the thought of tasting them.
If this sort of cultural crystallizing of custom and subsequent rationalizing or ritual sanctioning takes place among civilized and intelligent people, the like must occur among uncivilized tribes.
85. Agriculture
Attempts have been made to derive the invention of agriculture from climatic factors. The first theory was that farming took its rise in the tropics, where agriculture came naturally, almost without effort, under a bounteous sky. Only after people had acquired the habit of farming and had moved into other less favorably endowed countries, did they take their agriculture seriously in order to survive. But a second, equally plausible, and quite contradictory theory has been advanced, which looks toward the duress rather than the easy favors of nature. On the basis of conditions among the modern Papago Indians and the ancient inhabitants of the Southwest, it has been argued that it must have been the peoples of arid countries who invented agriculture, necessity driving them to it through shortage of wild supplies.
Between such flat opposites, the choice is merely one of unscientific guessing. In this particular case of the Southwest it is certain that both guesses are wrong. Agriculture did not come to the natives of this area because nature was favorable or because it was unfavorable. It came because through increase of knowledge and change of attitude, some people in the region of Southern Mexico or Guatemala or beyond first turned agriculturists, and from them the art was gradually carried, through nation after nation, to the Southwestern tribes, and finally even to the Indians of the North Atlantic coast.
The reasons for acceptance of this explanation are several. First is the distribution of native agriculture, whose practice was about equally spread in the two American continents with its middle in or near Central America. If a geographical diffusion of the art from a center took place, its radiation or extension would probably be about equal to the north and south. Then, the middle portions of the new world held the greatest concentration of native population, such as would have tended to produce a pressure in the direction of the establishment of agriculture and would also normally be a consequence of the continued custom of farming, as opposed to unsettled life. Again, the Southwestern tribes planted only maize, beans, and squashes; the Mexicans grew in addition tomatoes, chili peppers, cacao, and sweet potatoes. It looks as if they had carried their agriculture farther through having been at it longer. Then, pottery has evidently spread out from the same center, and the two arts seem to go hand in hand. Other evidence might be adduced, such as archæological excavations and the botanical fact that the home of the nearest wild relatives of the plants cultivated in the Southwest is the central or middle American area (§ [183]).
In short, the Southwestern Indians did not farm because nature induced them to make the invention. They did not make the invention at all. A far away people made it, and from them it was transmitted to the Southwest through a series of successive tribal contacts. These contacts, which then are the specific cause of Southwestern agriculture, constitute a human social factor; a cultural or civilizational factor. Climatic or physical environment did not enter into the matter at all, except to render agriculture somewhat difficult in the arid Southwest, though not difficult enough to prevent it. Had the Southwest been thoroughly desert, agriculture could not have got a foot-hold there. But this would be only a limiting condition; the active or positive causes that brought about the Southwestern agriculture are its invention farther South, the spread of the invention to the North, and its acceptance there.
Of course this conclusion sheds no light on the causes of the first invention in the middle American region. The ultimate origin of the phenomenon has not been penetrated. But the prevalence of agriculture in the aboriginal Southwest for several thousand years past has been pretty certainly accounted for, and by an explanation in terms of culture or civilization, or the activity of societies of human beings.