Résumé

One of the “top 125 questions of our time” pertains to why and how human culture came about (Science, 125th anniversary edition). One important step towards answering this question is to determine when human culture first appeared. There are two general possibilities. First, the human type of culture could have started preceding the split with the last common ancestor of apes and humans. Under this hypothesis, one would expect contemporary apes to show a human type of culture, too. Second, human culture could have evolved in hominins only (at least among primates) – i.e. it would then have evolved after the split with the last common ancestor. Under this second hypothesis, contemporary apes should likely lack the human type of culture. In my talk, I will argue for the second hypothesis. Additionally, commonly under the second hypothesis, the beginning of human culture is thought to coincide with the appearance of early stone tools. However, in my own version of this second hypothesis, I will argue instead that human culture evolved much later – namely, sometimes within the last half million years. My talk will consist of three parts. In Part 1 I will empirically show that contemporary ape culture is of a different type than human culture. Ape culture is “minimal culture” – not principally different from other animal cultures. In Part 2 – using indirect empirical evidence – I will show that the patterns we see across the earliest stone tools in the archaeological record are likewise best described by a minimal culture model. In Part 3 I will then present direct empirical evidence for this “minimal culture” model of early stone tools. I will conclude that – among primates – there is a specific type of culture that is shown today by humans alone (see below). Furthermore, I will conclude that this type of culture evolved very late in our lineage – a long time after the first stone tools appeared. The theoretical basis for my talk will be the basic insight – an accepted insight by now – that there are several different types of culture. The failure to acknowledge this fact lies at the heart of many misunderstandings within and across fields interested in cultural evolution. Problematically, often an all-encompassing “minimal definition” of culture alone is applied to various phenomena that should instead meaningfully be kept distinct. What is this minimal definition? In essence, the minimal definition of culture merely demands evidence that behaviour and/or behavioural products have been influenced by social learning of some type. The problem is that there are many types of social learning – with some being empirically rare. Failing to differentiate between social learning types has led to the predictable result that “culture“ has now been found in nearly any animal that has ever been studied – from ants to zebra finches; and of course, also in apes. The minimal definition of culture thus proved too wide to be useful for evolutionary examinations. We need to be more specific in our analysis, especially when we try to detect evidence for specific types of cultures – such as human culture. First, we know that human behaviours and artefacts are typically not just influenced by social learning. Instead, they very often fully depend on social learning. For example, no other ape species dances to arbitrary – yet precisely copied – dance steps, has language, or builds social and physical tools that could not be re-innovated from scratch by naïve subjects. This aspect is missed by the minimal culture definition. Second, most things humans do depend on a specific type of social learning – namely, on the copying of their underlying know-how. This skill – the copying of know-how – has allowed human know-how to culturally evolve. It evolved to levels unreachable by culturally unconnected individuals. As a result, human culture is specifically marked by producing supra-individual know-how. Neither ape cultures today, nor early stone tool cultures, consist of supra-individual know-how – likely for the simple reason that neither apes nor the early stone-tool producing hominins are/were able to copy such know-how from each other. The key skill of know-how copying has evolved on the human lineage alone – and this evolution happened much later than the appearance of early stone tools had formerly suggested.

Référence

Claudio Tennie (University of Tübingen), « Cumulative cultural evolution of know-how shows a late onset and a restriction to the human ape », IAST General Seminar, Toulouse : IAST, 11 octobre 2022, 11h30–12h30, salle Auditorium 4.