Baby girls born in the United States in 1970 had a fair chance of being named Jennifer—it was the most popular female baby name that year, and for many years thereafter. But Jennifer’s hold was stronger in the North than in the South: In New York and Wisconsin, for example, it was the number one name in 1970, whereas in Georgia and Alabama, Kimberly and Angela held the top two slots. Jennifer is part of a larger pattern, it turns out. Popular baby names in nearby states tend to be correlated with one another. But according to research published last week in the Proceedings of the National Academy of Sciences, the pattern of correlated states has shifted over time. In the video above, states with similar colors have similar distributions of names for baby girls. In the early 1900s, the northern and southern states showed a sharp divide. But that divide began to rearrange in the last part of the century, and by 2000, it was gone. Instead, states in the center of the country formed their own group, whereas states on the coasts were similar to one another. Although the research doesn’t clarify the reason for the rearrangement, the authors suggest that further studies could explain the shift. The results may help scientists understand how societal trends evolve and take hold, and researchers say the method could be applied to understanding other cultural traits.
(Video credit: P. Barucca, J. Rocchi, E. Marinari, G. Parisi, and F. Ricci-Tersenghi/PNAS)