What do we measure when we measure pubertal development? Conceptual challenges in measuring and interpreting pubertal effects on brain and behavior

Pubertal development is believed to influence cognitive and behavioral development during adolescence, but measuring puberty is challenging. Difficulties stem not only from practical issues, which have been extensively discussed in the literature, but also from the inherent complexity of pubertal development from a physiological perspective. Here we discuss conceptual issues related to measuring and interpreting pubertal effects on brain, cognitive, and behavioral development. Our analysis shows that all currently used measures, both those based on the assessment of external physical characteristics and those based on measuring relevant hormones form biological samples, share significant limitations that hinder their interpretation. These limitations arise from the fact that puberty is not a unitary phenomenon, cannot be measured directly nor be defined by individual makers, and its different markers are often discordant. Moreover, its effects on brain development, cognition, and behavior are bound to involve a complex causal thicket, requiring an integrative assessment of pubertal development. We argue that a possible compromise between practical issues (building feasible/reliable measures) and theoretical ones (building conceptually sound and interpretable measures) is to treat puberty as the variance shared among multiple pubertal indicators, combining physical markers and hormonal measures.