Maternal encouragement in nonhuman primates and the question of animal teaching.

Most putative cases of teaching in nonhuman animals involve parent-offspring interactions. The interpretation of these cases, particularly with regard to the cognitive processes involved, is controversial. Qualitative and quantitative observations made in nonhuman primates suggest that, in some species, mothers encourage their infants' independent locomotion and that encouragement can be considered a form of instruction. In macaques, experience in raising previous offspring accounts in part for variability between mothers in propensity to encourage infant motor skills. Parsimony suggests that the cognitive mechanisms underlying maternal encouragement of infant locomotion in primates as well as some other putative cases of animal teaching may involve first-order intentionality (i.e., goal-directed behavior) and not higher cognitive processes such as attribution of knowledge/ignorance or perspective-taking. Encouragement of infant independent locomotion early in life may have benefits to mothers later on, in terms of reduction of costs of infant carrying, earlier infant weaning, and increased probability of reproduction in the mating season. The elementary forms of teaching observed in nonhuman primates may have played an important role in the origin and evolution of human culture.