Conformist transmission evolves robustly across far more conditions than heavy social learning does

Evidence

By systematically varying r, the accuracy of environmental information, m, the migration rate, e, the degree of environmental stability, and n, the number of subpopulations, we have learned several important things about the evolution of social learning and conformist transmission. First, the degree of reliance on social learning (L) depends on strongly on the accuracy of environmental information (r) and the frequency of environmental fluctuations (1 2 e). The evolution of high values of L requires low-accuracy environmental information (r ø 0.5) and infrequent environmental shifts (e ø 1.0). In contrast, conformist transmission evolves to nearly maximum strength (D ø 1) over a much wider range of parameter combinations than does a strong reliance on social learning, provided there is at least a small amount of migration. In fact, although extreme variations in these parameters will prevent the evolution of conformist transmission, the set of parameter values under which conformist transmission fails to evolve is surprisingly small. — Joe Henrich and Robert Boyd, The Evolution of Conformist…, 65

1. Our model indicates that conformist transmission is favored by selection under a wide range of conditions. Conformist transmission evolves in fluctuating environments; it evolves when the accuracy of environmental information is poor and when it is fairly accurate. 2. Assuming that our model captures the conditions that shaped the evolution of social learning in humans, we have shown that natural selection favors increasing the reliance on social learning. And, there is no case in which a strong reliance on social learning evolves but conformist transmission does not. Thus, the fact that humans can imitate implies that conformism also is likely to be an important component of human social learning. — Joe Henrich and Robert Boyd, The Evolution of Conformist…, 121

3. In our model, the presence of a conformist effect increases the evolutionary equilibrium amount of social learning. Social learning becomes more prevalent when conformist genotypes are possible. — Joe Henrich and Robert Boyd, The Evolution of Conformist…, 121

To understand the conditions under which conformist transmission is adaptive, we constructed a model of the evolution of conformist transmission in an environment that varies in both space and time. We also allowed an individuals’ reliance on social learning to coevolve with conformist transmission and compete with individual learning. Because conformist transmission produces nonlinear dynamics, analytical results are difficult to achieve when environments change stochastically. Accordingly, we performed a number of computer simulations intended to explore the parameter space and illuminate the evolutionary dynamics of both conformist and unbiased transmission. The results of these simulations indicate that conformist transmission is favored in temporally varying environments under a broad range of conditions. In fact, the present results indicate that a strong conformist effect in social learning evolves under a wider range of conditions than does a heavy reliance on social learning—whatever the equilibrium reliance on social learning, it always contains a strong conformist effect. — Joe Henrich and Robert Boyd, The Evolution of Conformist…, 29

To model the genetic evolution of social learning and conformist transmission, we assume that an individuals’ propensity to imitate and the importance of the conformist bias in imitation are genetically variable. In particular, we assume a haploid genetic system with 400 alleles (at a single locus) that vary in both the degree of reliance on social learning and the strength of conformist transmission that they produce. — Joe Henrich and Robert Boyd, The Evolution of Conformist…, 49

By systematically varying r, the accuracy of environmental information, m, the migration rate, e, the degree of environmental stability, and n, the number of subpopulations, we have learned several important things about the evolution of social learning and conformist transmission. First, the degree of reliance on social learning (L) depends on strongly on the accuracy of environmental information (r) and the frequency of environmental fluctuations (1 2 e). The evolution of high values of L requires low-accuracy environmental information (r ø 0.5) and infrequent environmental shifts (e ø 1.0). In contrast, conformist transmission evolves to nearly maximum strength (D ø 1) over a much wider range of parameter combinations than does a strong reliance on social learning, provided there is at least a small amount of migration. In fact, although extreme variations in these parameters will prevent the evolution of conformist transmission, the set of parameter values under which conformist transmission fails to evolve is surprisingly small. Second, the presence of conformist transmission effectively increases the accuracy of social learning in most situations and consequently facilitates a greater reliance on social learning. — Joe Henrich and Robert Boyd, The Evolution of Conformist…, 65

Conformist transmission increases the equilibrium value of L by enhancing the effectiveness of social learning, even when the environment frequently switches. This result may seem counterintuitive until one realizes that conformist transmission acts to increase the accuracy of social learning by giving individuals a guide in accessing the more adaptive behavior. — Joe Henrich and Robert Boyd, The Evolution of Conformist…, 77

Categorization

• QUESTION: This ‘surprisingly small’ set of parameter values where conformism fails is the crux of the selection-based precursor to coercion-vulnerability — worth pinning down exactly which regimes fail.
• DEEPTHINKING: The asymmetry — conformism is easy to evolve, heavy reliance on social learning is hard — is the load-bearing empirical result this whole paper rests on and deserves careful re-reading.
• XREF: This is the core technical result Henrich later popularizes; connects to the reading purpose of checking when conformist transmission is favored. — connects to: Conformist transmission means copying the commonest behavior more than its frequency warrants; Conformism stays adaptive under rapid change though heavy social learning does not; Conformist transmission is favored only when some migration exists. — Joe Henrich and Robert Boyd, The Evolution of Conformist…, 86 (+6 more)
• DEFINE: Clarifies the key evolutionary finding of the model: conformism rides along with any imitative social learning.
• corroborated: 7 independent passages support this claim — Joe Henrich and Robert Boyd, The Evolution of Conformist…, 65; Joe Henrich and Robert Boyd, The Evolution of Conformist…, 121; Joe Henrich and Robert Boyd, The Evolution of Conformist…, 29 (+2 more)
• recurring: this claim recurs 2 times within its source

Related

• Natural selection favors conformist transmission under a wide range of conditions, including fluctuating environments. (similarity 0.91)
• Conformist bias evolution requires less environmental stability than social learning evolution itself. (similarity 0.88)
• Conformist transmission is favored only when some migration exists. (similarity 0.88)
• Conformist transmission means copying the commonest behavior more than its frequency warrants (similarity 0.88)
• Conformist transmission increases behavioral adoption odds above population frequency. (similarity 0.86)
• Evolutionary selection robustly favors copying the majority even when environments shift often. (similarity 0.85)
• Conformist transmission stays strong even when environmental cues are highly accurate or uninformative. (similarity 0.84)
• No flexible-learning scenario eliminates the adaptive need for conformity. (similarity 0.84)
• Conformist transmission occurs across many social-learning species. (similarity 0.84)
• Conformist transmission strength is a tunable model parameter. (similarity 0.84)
• Migration among subpopulations weakens reliance on social learning but barely affects conformist transmission strength. (similarity 0.84)
• Conformist transmission is favored across a broader range of conditions than mere social learning. (similarity 0.84)
• Selection favors conformist transmission in both spatially and temporally varying environments (similarity 0.82)
• Conformism stays adaptive under rapid change though heavy social learning does not (similarity 0.81)
• Conformist transmission biases learners toward adopting a population’s most frequent cultural traits. (similarity 0.81)

Broader Connections

• Learning and conformity are distinct processes, not interchangeable ones #expands (0.75)
• Learning and conformity are distinct psychological processes #expands (0.75) — John F. Dovidio, Peter Glick, Laurie A. Rudman, On the Nature of Prejudice, 2001
• Learning and conformity are distinct processes conflated by Allport #expands (0.72)
• Computer simulation can test hypotheses about large-scale social learning #responds-to (0.70) — Cailin O’Connor and James Owen Weatherall, The Misinformation Age, 47