Animal pointing: Changing trends and findings from 30 years of research.

The past 30 years have witnessed a continued and growing interest in the production and comprehension of manual pointing gestures in nonhuman animals. Captive primates with diverse rearing histories have shown evidence of both pointing production and comprehension, though there certainly are individual and species differences, as well as substantive critiques of how to interpret pointing or "pointing-like" gestures in animals. Early literature primarily addressed basic questions about whether captive apes point, understand pointing, and use the gesture in a way that communicates intent (declarative) rather than motivational states (imperative). Interest in these questions continues, but more recently there has been a dramatic increase in the number of articles examining pointing in a diverse array of species, with an especially large literature on canids. This proliferation of research on pointing and the diversification of species studied has brought new and exciting questions about the evolution of social cognition, and the effects of rearing history and domestication on pointing production and, more prolifically, comprehension. A review of this work is in order. In this article, we examine trends in the literature on pointing in nonhumans. Specifically, we examine publication frequencies of different study species from 1987 to 2016. We also review data on the form and function of pointing, and evidence either supporting or refuting the conclusion that various nonhuman species comprehend the meaning of pointing gestures. (PsycINFO Database Record (c) 2018 APA, all rights reserved).