Paradox of diversity in the collective brain

Abstract

Human societies are collective brains. People within every society have cultural brains—brains that have evolved to selectively seek out adaptive knowledge and socially transmit solutions. Innovations emerge at a population level through the transmission of serendipitous mistakes, incremental improvements and novel recombinations. The rate of innovation through these mechanisms is a function of (1) a society's size and interconnectedness (sociality), which affects the number of models available for learning; (2) fidelity of information transmission, which affects how much information is lost during social learning; and (3) cultural trait diversity, which affects the range of possible solutions available for recombination. In general, and perhaps surprisingly, all three levers can increase and harm innovation by creating challenges around coordination, conformity and communication. Here, we focus on the ‘paradox of diversity’—that cultural trait diversity offers the largest potential for empowering innovation, but also poses difficult challenges at both an organizational and societal level. We introduce ‘cultural evolvability’ as a framework for tackling these challenges, with implications for entrepreneurship, polarization and a nuanced understanding of the effects of diversity. This framework can guide researchers and practitioners in how to reap the benefits of diversity by reducing costs. This article is part of a discussion meeting issue ‘The emergence of collective knowledge and cumulative culture in animals, humans and machines’.

The emergence of collective knowledge and cumulative culture in animals, humans and machines

“…They argue that by splitting the burden of cultural knowledge across individuals in this way, social ratcheting has become a key component of human collective intelligence. Such conclusions from these real-world investigations converge encouragingly with reports from various laboratory and modelling studies in this issue [ 98 , 99 , 105 , 106 , 108 , 159 , 160 ].…”

“…Recognizing this, but going far beyond it, articles in this issue address the significance of cases where collective knowledge exists only at the level of the collective, and not in any one individual. The partial or variant knowledge of different individuals that this implies may be distributed across a population in space, and/or over time, with subsequent combinations thence leading to innovations that can drive CCE [ 82 , 93 , 153 – 155 , 159 , 160 ]. Studies are progressively revealing that how these effects play out may be shaped by numerous interacting factors including the form of social structures and networks [ 93 , 159 , 160 ], relationships between individuals such as in degree of tolerance [ 153 ] or coordination [ 157 ], adaptive biases in model selection such as conformity [ 153 , 163 ], and the socio-cognitive capabilities of participant individuals, such as theory of mind [ 29 , 158 ] and inventiveness.…”

“…The partial or variant knowledge of different individuals that this implies may be distributed across a population in space, and/or over time, with subsequent combinations thence leading to innovations that can drive CCE [ 82 , 93 , 153 – 155 , 159 , 160 ]. Studies are progressively revealing that how these effects play out may be shaped by numerous interacting factors including the form of social structures and networks [ 93 , 159 , 160 ], relationships between individuals such as in degree of tolerance [ 153 ] or coordination [ 157 ], adaptive biases in model selection such as conformity [ 153 , 163 ], and the socio-cognitive capabilities of participant individuals, such as theory of mind [ 29 , 158 ] and inventiveness. The findings of the studies in this issue, alongside recent complementary explorations [ 91 , 162 , 164 ], provide a deepening understanding of the diverse manifestations of culture and its evolution in both natural and human-engineered contexts.…”

“…Schimmelpfennig et al . [ 159 ] review studies addressing how ‘cultural evolvability’ can be either enhanced or inhibited by variations in the three principal influences: social structure (e.g. connectedness), transmission fidelity and cultural trait diversity.…”

The origins of human cumulative culture: from the foraging niche to collective intelligence

“…Various studies have argued that cumulative cultural evolution requires cognitive mechanisms including transmission fidelity [ 17 ], innovation [ 18 ], teaching [ 19 ], shared intentionality [ 7 , 20 ], cultural specialization [ 21 , 22 ] and recombination [ 23 ], as well as demographic conditions such as large population size and connectivity [ 24 ]. However, why those features only evolved in some hominins remain unknown.…”