title: Cross-correlations of American baby names.
abstract: 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.
authors.affiliation: Dipartimento di Fisica, Sapienza Universitá di Roma, I-00185 Rome, Italy; giorgio.parisi@roma1.infn.it baruccap@sns.it.
authors.forename: Paolo
authors.initials: P
authors.lastname: Barucca
authors.affiliation: Dipartimento di Fisica, Sapienza Universitá di Roma, I-00185 Rome, Italy;
authors.forename: Jacopo
authors.initials: J
authors.lastname: Rocchi
authors.affiliation: Dipartimento di Fisica, Sapienza Universitá di Roma, I-00185 Rome, Italy; Sezione di Roma 1, Istituto Nazionale di Fisica Nucleare, I-00185 Rome, Italy.
authors.forename: Enzo
authors.initials: E
authors.lastname: Marinari
authors.affiliation: Dipartimento di Fisica, Sapienza Universitá di Roma, I-00185 Rome, Italy; Sezione di Roma 1, Istituto Nazionale di Fisica Nucleare, I-00185 Rome, Italy giorgio.parisi@roma1.infn.it baruccap@sns.it.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Parisi
authors.affiliation: Dipartimento di Fisica, Sapienza Universitá di Roma, I-00185 Rome, Italy; Sezione di Roma 1, Istituto Nazionale di Fisica Nucleare, I-00185 Rome, Italy.
authors.forename: Federico
authors.initials: F
authors.lastname: Ricci-Tersenghi
mesh_terms: D006801:Humans; D007231:Infant, Newborn; D009275:Names; D014481:United States
keywords: clustering; complex systems; cultural evolution; cultural traits