(A) Time series of mean cultural complexity over time in Model 2 at different population sizes, N, under the assumption of direct bias. (B) Relationship between maximum cultural complexity
max and N for direct bias, indirect bias and unbiased transmission, and with N plotted on a logarithmic scale. For direct bias, maximum cultural complexity
max increases logarithmically with N up to N = 100 (line is a logarithmic best-fit with R2 = 0.991 for N≤100), after which it plateaus. For indirect bias, a similar logarithmic increase followed by a plateau occurs to that under direct bias, but the values of
max are lower and the plateau occurs at higher values of N (around N = 1000; line is a logarithmic best-fit with R2 = 0.994 for N≤1000). For unbiased transmission, N has no effect on
max. Parameters: ci = 10, cs = 5, λ = 1000, µi = µs = 0, all results are the average of 100 independent runs.