The frequency of a cultural trait can influence its tendency to be copied. We develop a maximum-likelihood method to measure such frequency-dependent selection from time series data, and we apply it to baby names and purebred dog preferences over the past century. The form of negative frequency dependence we infer among names explains their diversity patterns, and it replicates across the United States, France, Norway and the Netherlands. We find different growth rates for male versus female names, attributable to different rates of innovation, whereas biblical names enjoy a genuine selective advantage at all frequencies, which explains their predominance among top names. We show how frequency dependence emerges from a host of underlying selective mechanisms, including a preference for novelty that recapitulates boom–bust fads among dog owners. Our analysis of cultural evolution through frequency-dependent selection provides a quantitative account of social pressures to conform or to be different.

文化特征的频率会影响其被复制的趋势。我们开发了一种最大似然方法来从时间序列数据中测量这种与频率相关的选择，并将其应用于过去一个世纪的婴儿名字和纯种狗偏好。我们在名称中推断出的负频率依赖性形式解释了它们的多样性模式，并且它在美国、法国、挪威和荷兰都得到了复制。我们发现男性和女性名字的增长率不同，这归因于不同的创新率，而圣经名字在所有频率上都享有真正的选择优势，这解释了它们在顶级名字中的优势。我们展示了频率依赖性是如何从一系列潜在的选择机制中产生的，包括对狗主人的繁荣与萧条时尚的偏好。