Cross-correlations of American baby names
Significance Societal and cultural transformations are very general and debated topics, both by scientists (e.g., sociologists) and by public opinion (e.g., artists, music producers, brand manufacturers, and advertising agencies). Although almost everyone would be able to express a position on such arguments, it is much more difficult to support such an opinion based on scientific evidence. In this work we analyze the case of American baby names and describe the evolution of tastes of parents regarding the choice of the name during the years of the last century. Using quantitative methods we find that a deep transformation occurred at the end of the 20th century and suggest that this might be studied from a quantitative sociological point of view. The quantitative description of cultural evolution is a challenging task. The most difficult part of the problem is probably to find the appropriate measurable quantities that can make more quantitative such evasive concepts as, for example, dynamics of cultural movements, behavioral patterns, and traditions of the people. A strategy to tackle this issue is to observe particular features of human activities, i.e., cultural traits, such as names given to newborns. We study the names of babies born in the United States from 1910 to 2012. Our analysis shows that groups of different correlated states naturally emerge in different epochs, and we are able to follow and decrypt their evolution. Although these groups of states are stable across many decades, a sudden reorganization occurs in the last part of the 20th century. We unambiguously demonstrate that cultural evolution of society can be observed and quantified by looking at cultural traits. We think that this kind of quantitative analysis can be possibly extended to other cultural traits: Although databases covering more than one century (such as the one we used) are rare, the cultural evolution on shorter timescales can be studied due to the fact that many human activities are usually recorded in the present digital era.