29.03.2022 Claudio Tennie

Culture is often defined as behaviour and/or behavioural products, influenced by social learning. This approach may be called the "wide net" definition of culture: it allows the study of (this kind of) culture across the animal kingdom, where it is indeed frequently found. The most widely known cases of such culture pertain to the cultures of non-human great apes (henceforth aps); i.e. to apes’ patchy distribution of behaviour and tool usage. But human behaviours and human artefacts are not only merely influenced by social learning; they often fully depend on social learning: 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 on the spot by naïve subjects. All these things not only depend on continued social learning. They are additionally marked by requiring a specific kind of social learning – namely, the cultural transmission of their underlying know-how. That is, the human ape, and the human ape alone, has produced and continues to produce (and maintain) what may be called “cultural dependent know-how” (CDKH). In my talk will argue that the data available strongly points to a lack of sufficient spontaneous skills of know-how copying in other apes. Because of this, one would expect that these other apes lack cultural dependent know-how. This is because this special type of know-how can only exist due to past cultural evolution – and where this evolution necessitates an unbroken cultural transmission of know-how. And this requires, at minimum, sufficient skills of know-how transmission. Again, while we clearly do see culture in apes, this is fully to be expected given how wide a net the current cultural definition uses. It is therefore not the case that apes do not have culture – and neither will I argue this here. But what apes lack is the type of culture that humans show today. Humans, but not other apes, show cultural evolution of know-how – maintained at supra-individual levels. Several predictions of this hypothesis can be derived. The three most important predictions are the following. 1. Apes should not spontaneously copy supra-individual know-how. 2. Know-how shown by an ape species in one population should be re-innovatable on the spot by individuals in other, culturally unconnected, populations. 3. Ape cultural patterns as those seen today should be able to come about in the absence of supra-individual know-how copying. In my talk I will show multiple lines of empirical evidence that support all these three predictions. In summary, ape culture is fundamentally different from human culture, which raises the question when human culture began to be special. Recent work from my group shows that this cultural evolution of know-how has had a surprisingly late onset in our own lineage. Much of the currently assigned early evidence for modern types of human culture (i.e. many early stone tool types) require a new interpretation given their patterns of stasis in their re-innovatibility from scratch. The earliest manifestations of these tools are thus better explained by an ape cultural model than they are by a human cultural model. For a long time, early hominins were therefore forced to constantly “reinvent know-how” in each generation, leading to the observed stasis of early stone tools in the archeological record. Apes today continue to reinvent their know-how in each generation. In contrast, humans continue to pass on the know-how of past generations, and to cumulatively build on it.