The emergence of moral foundations in children's speech

A study of children's conversations with their caretakers sheds light on the timeline of the emergence of moral foundation words in the first six years of life in English-speaking children. Moral Foundations theory posits that morality is largely intuitive and underlaid by modular foundations. The original set of five foundations proposed by researchers includes Care/Harm, Fairness/Cheating, Authority/Subversion, Loyalty/Betrayal, and Purity/Degradation.

Aida Ramezani and colleagues systematically identified words related to these moral foundations in 44 text corpora from the CHILDES dataset, a large database of transcripts of children's speech used by researchers, seeking to establish a timeline for the emergence of these ideas in children's lexicons. Words that appear in contexts relevant to moral foundations are extracted from dyadic conversations between children and caretakers.

The authors find that children use words related to Care/Harm at much higher rates than all the other foundations. Care/Harm and Fairness/Cheating, which focus on benefits to the individual and are thus known as "individualizing foundations," emerge earlier than Authority/Subversion, Loyalty/Betrayal, and Purity/Degradation, which focus on benefits to a wider group and are thus known as "binding foundations." The Care/Harm foundation is present in the speech of one-year-olds, in utterances such as "help Carrie wash dish."

Caretakers speak more often about Purity/Degradation than children do. According to the authors, caretakers tend to talk about fairness, while children tend to talk about cheating, in utterances such as the childhood classic: "That's not fair!"

The research was published in PNAS Nexus.