Towards a three-level neo-Tinbergenian approach to object play: Structure, causes and consequences of a behavioral puzzle

My main goal in this paper is to propose a reformulation of foundational models in behavioral research, including Tinbergen's (1963) well-known four levels of analysis (namely, ontogenetic, mechanistic, functional, and evolutionary questions) and Mayr's (1961) dichotomy between proximate and ultimate causations. After critically evaluating these influential but problematic models, I present a three-level neo-Tinbergenian approach to behavior that considers the triadic integration of behavioral causes, structure, and consequences along a single temporal continuum. I then argue that object-directed play is a good candidate behavior to apply this new paradigm by presenting significant examples of the combined analysis of at least two of these three levels. Finally, I show how stone handling, a form of culturally-transmitted object play in macaques, is perfectly amenable to this unified three-level explanatory framework. My proposed approach fits recent theoretical and empirical advances in behavioral biology, has a heuristic value, and may provide numerous benefits to a range of behavioral scientists.

Professor Masao Kawai, a pioneer and leading scholar in primatology and writer of animal stories for children

This Editorial is dedicated to Professor Masao Kawai (Fig. 1), who passed away on May 14th, 2021. He served as the sixth Editor-in-Chief of Primates for 15 years (1981-1995). The following is a collection of memories from 20 scholars. Fig. 1 Professor Masao Kawai, a pioneer and leading scholar in primatology (photo taken in January 2020; Courtesy of Ryoko Kawai).

Cumulative culture in nonhumans: overlooked findings from Japanese monkeys?

Cumulative culture, generally known as the increasing complexity or efficiency of cultural behaviors additively transmitted over successive generations, has been emphasized as a hallmark of human evolution. Recently, reviews of candidates for cumulative culture in nonhuman species have claimed that only humans have cumulative culture. Here, we aim to scrutinize this claim, using current criteria for cumulative culture to re-evaluate overlooked qualitative but longitudinal data from a nonhuman primate, the Japanese monkey (Macaca fuscata). We review over 60 years of Japanese ethnography of Koshima monkeys, which indicate that food-washing behaviors (e.g., of sweet potato tubers and wheat grains) seem to have increased in complexity and efficiency over time. Our reassessment of the Koshima ethnography is preliminary and nonquantitative, but it raises the possibility that cumulative culture, at least in a simple form, occurs spontaneously and adaptively in other primates and nonhumans in nature.

A multidisciplinary view on cultural primatology: behavioral innovations and traditions in Japanese macaques

Cultural primatology (i.e., the study of behavioral traditions in nonhuman primates as a window into the evolution of human cultural capacities) was founded in Japan by Kinji Imanishi in the early 1950s. This relatively new research area straddles different disciplines and now benefits from collaborations between Japanese and Western primatologists. In this paper, we return to the cradle of cultural primatology by revisiting our original articles on behavioral innovations and traditions in Japanese macaques. For the past 35 years, our international team of biologists, psychologists and anthropologists from Japan, France, Sri Lanka, the USA and Canada, has been taking an integrative approach to addressing the influence of environmental, sociodemographic, developmental, cognitive and behavioral constraints on the appearance, diffusion, and maintenance of behavioral traditions in Macaca fuscata across various domains; namely, feeding innovation, tool use, object play, and non-conceptive sex.