Diverging trends in the age of social and biological transitions to adulthood

We discuss how different disciplines vary in their definitions of what constitutes the transition to adulthood and the age at which this transition is attained. This review synthesizes diverse perspectives on conceptualizing adulthood, exploring markers from demographic, economic, legal, cultural, subjective, psychological, and biological domains-each offering unique insights. We discuss how this life transition has changed over time and across different contexts. We find that while socioeconomic markers such as entering the labor market and first childbirth are increasingly being delayed in contemporary societies, biological markers like puberty occur earlier, while institutional and legal markers of the transition are often constant. Consequently, individuals now experience extended periods of biological maturity before achieving social adulthood. This review highlights the complexities of defining adulthood and underscores the need for an updated and multidisciplinary examination of this significant life stage transition.