Abstract
Recent studies in several taxa have demonstrated that animal culture can evolve to become more efficient in various contexts ranging from tool use to route learning and migration. Under recent definitions, such increases in efficiency might satisfy the core criteria of cumulative cultural evolution (CCE). However, there is not yet a satisfying consensus on the precise definition of efficiency, CCE or the link between efficiency and more complex, extended forms of CCE considered uniquely human. To bring clarity to this wider discussion of CCE, we develop the concept of efficiency by (i) reviewing recent potential evidence for CCE in animals, and (ii) clarifying a useful definition of efficiency by synthesizing perspectives found within the literature, including animal studies and the wider iterated learning literature. Finally, (iii) we discuss what factors might impinge on the informational bottleneck of social transmission, and argue that this provides pressure for learnable behaviours across species. We conclude that framing CCE in terms of efficiency casts complexity in a new light, as learnable behaviours are a requirement for the evolution of complexity. Understanding how efficiency greases the ratchet of cumulative culture provides a better appreciation of how similar cultural evolution can be between taxonomically diverse species—a case for continuity across the animal kingdom.This article is part of a discussion meeting issue ‘The emergence of collective knowledge and cumulative culture in animals, humans and machines’.
Highlights
There are a growing number of examples of cultures [1] in non-human animals, with such socially learned, group-specific patterns of behaviours found in a variety of phylogenetic taxa, including primates [2,3,4], birds [5,6], cetaceans [7,8,9] and insects [10]
The extended criteria include aspects of the more complex and open-ended cultural traits found in humans, such as chaining of multiple traits, diversification, recombination between cultural lineages, cultural exaptation and cultural niche construction [49]. We extend this recent framing of cumulative cultural evolution (CCE) by focusing on performance in terms of efficiency, as efficiency is the most common focus in animal cultural evolution studies, especially in species where tool use is absent
We extend the concept of informational bottleneck of social transmission from the evolutionary linguistics and cognitive science literature to the debate on CCE across species, and identify constraints that influence this bottleneck in wild populations
Summary
There are a growing number of examples of cultures [1] in non-human animals ( animals), with such socially learned, group-specific patterns of behaviours found in a variety of phylogenetic taxa, including primates [2,3,4], birds [5,6], cetaceans [7,8,9] and insects [10]. In a systems or informational approach, complexity correlates with randomness, or unpredictability, in the sense that the more disordered the system is the more information it takes to define that system (e.g. Shannon entropy [41]) This definition is potentially compatible with definitions of complexity such as behavioural or toolkit diversity, as it is possible to consider the number of behaviours or tools, plus their usage frequency over some time interval as a macrostate, upon which an entropy measure could be taken. We extend this recent framing of CCE by focusing on performance in terms of efficiency, as efficiency is the most common focus in animal cultural evolution studies, especially in species where tool use is absent. We discuss how efficiency offers a pathway for the evolution of complex cultural traits
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
