Keynote 1: Prof. Carel van Schaik, University of Zurich
Carel van Schaik is interested in the origins of technology and culture. He explores to what extent non-human great ape behaviours are cultural and aims to explain the apparent absence of cumulative culture in great apes. 

Why us? On the evolution of the capacity for cultural evolution in our lineage
The Miocene was the era of the apes; by the end of the Pleistocene they were almost gone. Yet one member of this declining clade thrived: hominins. The secret of our success (to quote Joe Henrich) is our ability to develop and improve cultural solutions to numerous problems: cumulative cultural evolution. Why did only one member of this declining clade discover this successful recipe for fast and near-perfect local adaptation, even though there were numerous others with a very similar foundation? Various answers have been suggested, but here we would like to examine the idea that argues for major motivational changes, rather than cognitive ones, that put our ancestors on the road to cumulative culture: proactive prosociality. Teaching and pedagogy of sorts characterized our ancestors, presumably from the time of Homo erectus, and reflect the adoption of extensive allomaternal care. We will therefore examine both the comparative distribution of teaching and the paleo-archeological record. We will also think aloud about the role of language.


Keynote 2: Prof. Emer. Peter Richerson, University of California, Davis
Peter Richerson uses experiments, modelling, and observational studies to illuminate processes of (cumulative) cultural evolution. His work has been highly influential for the field of cultural evolution research. 

Cumulative Cultural Evolution as Collective Cognition
Humans do an amazing variety of very clever things. We are said to be the most intelligent animal. Some writers argue that individual intelligence is responsible for our cleverness. A competing hypothesis is that it is not so much that individuals are intelligent but that populations of individuals collaborating over many generations that are the more important root of our genius. We understand to some approximation what cognitive elements are required to make cumulative culture. What is less clear is why this system evolved recently and only in our lineage. In theory, spatial and temporally varying environments can favor a costly system of social learning. The scales of temporal and spatial variation must be intermediate. At large scales, genes are the most efficient adaptive system and at short scales individual learning and similar systems are most efficient. The Pleistocene pattern of high spatio-temporal variation at intermediate scales is plausibly the main factor favoring cumulative culture, combined with preadaptations for tool-making and social life. Recent long high resolution core data suggest that the intermediate frequency temporal variation has increased progressively over the last few glacial cycles, in parallel with human brain size increase and cultural sophistication.


Keynote 3: Dr Rachel Kendal, University of Durham
Rachel Kendal’s work explores social learning, innovation, and social transmission in humans and non-human animals as well as their ability to understand cumulative culture.

What is cumulative culture, who has it, and why might this be?
Cumulative cultural evolution is widely held to be responsible for humanity’s outstanding success in colonising virtually every terrestrial habitat on the planet and solving countless ecological, social and technological challenges in the process.  Although many nonhuman species use social information in acquiring survival information, and exhibit behavioural traditions, the evidence for cumulative culture outside of humans is limited, at best.  However, in order to make such statements and investigate this potential bastion of human ‘uniqueness’ we must carefully consider how we define it.  We may posit that cumulative culture requires individuals to build upon the knowledge of previous generations such that trait complexity or efficiency evolves over time, resulting in traits that no individual could reproduce within their own lifetime.  I will discuss the intricacies of such definitions and their implications for determining the apparent distribution of cumulative culture across the animal kingdom.  In doing so, research published with colleagues a few years ago (Dean et al. 2012; 2013) and more recent developments in the literature will be reviewed.  In determining what underlies the apparent distribution of cumulative culture in the animal kingdom, the importance of socio-cognition, in particular transmission biases will be highlighted.  Such biases (context biases and content biases including cultural attractors) enable individuals to avoid costs associated with asocial learning, and determine when they use social information and from whom they acquire it.  As such, transmission biases may facilitate or constrain cumulative cultural evolution.


Keynote 4: Dr Olivier Morin, Max-Planck-Institute for the Science of Human History, Jena
Olivier Morin is a researcher in theoretical cognitive anthropology. His work focuses on cultural transmission and stabilization and integrates perspectives from anthropology, psychology, and the philosophy of social science.

Burying the Ratchet
The gradual accumulation of small improvements arrived at by chance can produce complex design, given enough time. This recipe for progress requires highly faithful preservation mechanisms: only a blindly accurate record can take advantage of random changes that yield their beneficial effects in the long run and in combination with many others. In neo-Darwinian biology, this ”ratchet mechanism” is supposed to be implemented by faithful DNA replication. It is tempting to try and find a behavioral mechanism that would provide a cultural equivalent for this biological ratchet: a mechanism that preserves the information contained in behaviours in a blind and faithful way. Whether this role is best fulfilled by emulation, imitation, over-imitation or something else is moot; but the view that a “ratchet effect” made possible by faithful copying mechanisms underlies human progress is often touted as fact. This view, however, is hardly ever confronted with the historical data that could refute it. This talk will argue that ratcheting is, in fact, not the most important source of technological progress (certainly not for recent and well-known changes, and arguably not for less recent, and less well known, changes). Disruptive change and foresighted invention matter more. These things can be helped by long-term cultural transmission, but do not need blind or faithful ratcheting to create progress. One implication for students of cultural transmission is that we should not limit ourselves to interactions that preserve or replicate behaviours (like imitation or its many cousins), but also consider things like communication or argumentation, which need not involve any ratcheting. Biologists originally borrowed the doctrine of gradual progress from conservative social theory. The import proved quite successful in biology, but we should resist feeding it back to social scientists.


Keynote 5: Prof. Alex Mesoudi, University of Exeter
Alex Mesoudi studies human cultural evolution and social learning using lab experiments and theoretical models. His work also investigates why cumulative culture seems to appear only in humans.

Cumulative Culture’s Catalysts and Constraints: Transmission Fidelity, Population Size and Acquisition Costs
Cumulative culture is arguably unique to our species and underpins our extraordinary ecological success. We learn from others that which no single individual could invent or discover alone, because knowledge is preserved and accumulated within and across generations. I will present some theoretical models, historical case studies and lab experiments that have explored both the factors that allow or facilitate cumulative culture (‘catalysts’), as well as factors that prevent or hinder it (‘constraints’). One model (Kempe, Lycett & Mesoudi 2014, J. Theor. Biol.) showed that cumulative culture emerges from non-cumulative cultural traditions when social learning is relatively accurate (but not necessarily perfectly accurate) and when there are multiple demonstrators from whom to learn. That both of these factors are needed, rather than there being a single key driver, might explain why cumulative culture is so rare in nature. The finding that cumulative culture depends on population size was shown experimentally using a task – solving jigsaw puzzles – in which multiple solutions can be combined additively (Kempe & Mesoudi, 2014, Evol. Human Behav.). This highlights the need to consider the nature of the task being solved, as some tasks may be more conducive to accumulation than others. A final model (Mesoudi, 2011, PLOS ONE) examined possible constraints on cumulative culture, particularly cases such as science and technology where knowledge increases exponentially. If knowledge in a population increases over time (which it does, by definition, if culture is cumulative), and if each generation must acquire this ever-increasing pool of knowledge in order to accumulate further, then there comes a point at which accumulation stops, where there is so much knowledge to acquire that there is no time left for innovation. While this is obviously a hypothetical situation, it logically follows from common assumptions about cumulative culture, and it instructively highlights their potential (lack of) validity.