Figure 2.
Gumbel probability distribution of imperfect transmission, based on Henrich [69]. Analyses by Kobayashi & Aoki [88] confirm that this logic is not specific to Henrich's chosen distribution. For a given skill value zi, the probability of acquiring a lower level skill (the portion of the distribution to the left of the dashed line) is less than the probability of acquiring an equal or greater skill level (the portion of the distribution to the right of the dashed line): learning is prone to error. As sociality and access to cultural models increases (e.g. through increased population size or density), there is a greater probability of at least one learner possessing skill level zi or greater and becoming the most skilled cultural model from whom the next generation learns. These assumptions and logic predict a relationship between sociality and equilibrium cultural complexity.