This structured population model is built to address how migration (or intergroup cultural transmission), copying error, and time-averaging affect regional variation in a single selectively neutral discrete cultural trait under different mechanisms of cultural transmission. The model allows one to quantify cultural differentiation between groups within a structured population (at equilibrium) as well as between regional assemblages of time-averaged archaeological material at two different temporal scales (1,000 and 10,000 ticks). The archaeological assemblages begin to accumulate only after a “burn-in” period of 10,000 ticks. The model includes two different representations of copying error: the infinite variants model of copying error and the finite model of copying error. The model also allows the user to set the variant ceiling value for the trait in the case of the finite model of copying error.

This version of the accumulated copying error (ACE) model is designed to address the following research question: how does finite population size (N) affect the coefficient of variation (CV) of a continuous cultural trait under the assumptions that the only source of copying error is visual perception error and that the continuous trait can take any positive value (i.e., it has no upper bound)? The model allows one to address this question while assuming the continuous trait is transmitted via vertical transmission, unbiased transmission, prestige biased transmission, mean conformist transmission, or median conformist transmission. By varying the parameter, p, one can also investigate the effect of population size under a mix of vertical and non-vertical transmission, whereby on average (1-p)N individuals learn via vertical transmission and pN individuals learn via either unbiased transmission, prestige biased transmission, mean conformist transmission, or median conformist transmission.