The relationship between environmental stability, <i>c</i> (where the environment changes every <i>c</i> generations) and the average number of cultural traits in a population (averaged over the final 500 generations of a 1000 generation run for 5 independent runs). Red lines indicate low environmental harshness (<i>h</i>=1), and blue lines indicate high environmental harshness (<i>h</i>=1.1). Dash-dot lines: <i>N</i>=5, solid lines: <i>N</i>=100, dashed lines: <i>N</i>=250, where <i>N</i> is population size. β=0.99. Error bars indicate the standard error of the mean. Compare to Figure 2 in the text where β=0.9
