Dr. Marceau has helped to advance our understanding of how genes and environments work together to predict child behavioral outcomes, with a particular focus on developmental psychopathology and transitions to substance use during adolescence. Her research examines the integrated roles of genetics, prenatal environmental risks, neuroendocrine development, and the family environment for human development by clarifying the magnitude of the effects of diverse factors that are typically evaluated in isolation. Examining effects in isolation is vital for in-depth understanding of specific mechanisms in controlled settings but can be misleading in the context of the complexity and diversity of human development. She has written both empirical and theoretical papers describing how these multiple processes may work together to help shape child and adolescent developmental outcomes, for example documenting distinct pathways by which stress hormones mediate genetic, prenatal, and parenting influences on children’s emotional (but not behavioral) problems, and adolescent substance use. Her work also finds that prenatal exposures are often related to genetic risk but can exert unique effects or modify both genetic and postnatal environmental effects on hormones and behavior. By leveraging unique behavioral genetic designs and statistical methods, Dr. Marceau’s work has challenged some and strengthened some causal claims of environmental influences on development, while revealing the ways in which biological and environmental factors work together to support human development broadly. Dr. Marceau’s work has been funded by the National Institute on Drug Abuse as a PI (F31, K01), Co-I (R01), and as primary sponsor/mentor on student-led (R36, F31) grants.