Universality as a Criterion of Native Reactions
The fundamental sign or criterion of a native trait, in accordance with what we have been saying, is that it shall make its appearance when there has been no chance to acquire it through experience. This is the one perfect criterion; but unfortunately it cannot always be applied, especially with a slowly maturing and much-learning species such as the human. We need other criteria, and one of some value is the criterion of universality.
Consider, for example, the attraction between the sexes, and ask whether this represents a native tendency, or whether each individual acquires it, as he does his "native language", by learning from his elders. Before the body reaches sexual maturity, there has been abundant opportunity for the quick-learning child to observe sex attraction in older people. Yet it is highly improbable that the liking for the other sex which he begins to show strongly in youth is simply an acquired taste. It is improbable because the attraction between the sexes is so universal not only among mankind but among birds and mammals and, indeed, practically throughout the animal kingdom.
Fighting is a similar case. Not so universal as the sex instinct, it still appears almost universally among birds and mammals.
The human individual is an animal, and some of his native traits are universal among animals. He is a vertebrate, and some of his traits, though not present in all animals, are universal among vertebrates. He is a mammal, with mammalian traits; a primate, with primate traits; a man with human traits; a Chinaman or Indian or European with racial traits; belongs to a more or less definite stock or breed within the race, and possesses the traits that are common to members of that stock; and the same with family traits. The criterion of universality, in the light of these facts, comes down to this: that when all individuals having the same descent show a trait in common, that trait is to be regarded as belonging to their native constitution--unless evidence can be brought forward to the contrary.
Smoking is universal among many Malay peoples, but we know, as a historical fact, that it was introduced among them after the discovery of America, not very many generations ago. Superstition is universal among some peoples, but we see the superstitious beliefs and practices taught by the older to the younger generation. Similarly with any specific language. It may very well be true in such cases that the universal practice appeals to some native tendency of the people; but the specific practice is handed down by tradition and not by inheritance.