Figure 6. The effect on maximum cultural complexity _max of varying (A) lifetime effort budget λ (with constant c_i = 10, c_s = 5), (B) innovation cost c_i (with constant c_s = 1, λ = 100), and (C) copying cost c_s (with constant c_i = 10, λ = 100).

Circles indicate direct bias, crosses indicate indirect bias and triangles indicate unbiased transmission. Lines show best-fit functions, in (A) showing a positive linear relationship between _max and λ for direct bias (R² = 0.999), indirect bias (R² = 0.991) and unbiased transmission (R² = 0.998); in (B) showing a negative linear relationship between _max and c_i for direct bias (R² = 0.995) and unbiased transmission (R² = 0.999), but for indirect bias only for larger c_i values (for c_i>30, R² = 0.990), with lower c_i values generating lower _max values than expected (no best-fit line drawn); and in (C) showing an inverse power law relationship between _max and c_s for direct bias (R² = 0.997), indirect bias (R² = 0.997) and unbiased transmission (R² = 0.992). Other parameters: N = 100, X = 100, µ_i = µ_s = 0, all results are the average of 100 independent runs.