My research focuses on brain and behavioral development during adolescence.  In the past, I have studied parent-adolescent relations, psychosocial maturity, school performance, after-school employment, developmental psychopathology, and juvenile justice. My current projects fall into these broad categories:

Adolescent Decision-Making

My work on adolescent decision-making examines the ways in which core psychological processes that affect judgment, decision-making, and risk-taking develop between the years of 10 and 30. I am especially interested in the implications of this research for legal and social policies affecting teenagers and young adults, particularly in the context of criminal law.

Age Differences in Decision-Making Across Cultures. In collaboration with Jennifer Lansford and Ken Dodge, at Duke University, and an international team of investigators, I am studying whether the pattern of development observed in the core components of decision-making identified in our studies of Americans are seen in other countries as well. We are currently in the field collecting data from samples of 10- to 30-year-olds in China, Colombia, Cyprus, India, Italy, Jordan, Kenya, the Philippines, Sweden, Thailand, and the United States (400 persons in each locale). Data collection is complete and data analysis is underway. The project is funded by the Jacobs Foundation.

Parenting Across Cultures. In many of the same countries in which we are studying age differences in decision-making, the same team of researchers is continuing a longitudinal study of children and their parents, begun when the children were 8 years old, to examine how various disciplinary practices affect children’s development, risky behavior, aggression, and decision-making. We have completed the collection of data up through age 10 and are currently in the field collecting the next wave. We have funding from NICHD to continue this research through age 17.

Adolescent Development and Criminal Culpability. As part of a series of projects overseen by the MacArthur Foundation Research Network on Law and Neuroscience, I am collaborating with a team of neuroscientists (B.J. Casey, Adriana Galvan, Jason Chein, Damien Fair) and legal scholars (Richard Bonnie and Elizabeth Scott) to examine changes in neural processes and behaviors between the ages of 8 and 24 that have implications for how we judge juvenile offenders’ criminal culpability. Data will be collected in Los Angeles and New York. We will be using the decision-making battery used in the cross-national study and are currently pilot testing tasks to be used in the fMRI scanner.  This project is funded by the MacArthur Foundation.

Neural and Behavioral Correlates of Peer Influences on Adolescent Behavior 

My work on the neural and behavioral correlates of peer influences on adolescent behavior is grounded in the observation that, in the real world as well as the experimental laboratory, adolescents, but not adults, take more risks in the presence of their peers than they do when they are alone. We have been using fMRI as well as behavioral methods to better understand why this is true. Some of our work involves the development and validation of new tasks and techniques to measure risk-taking, reward-seeking, response inhibition, and peer influence.

Peer Influences on Adolescent Risk-Taking. At our lab at Temple University, Jason Chein and I are studying the neural and behavioral factors that account for the peer effect.  In an study for which data collection is complete, we have been imaging adolescents’ and adults’ brain activity while they are performing various types of decision-making tasks either with or without being observed by their peers. This research has been funded by NIDA.

The Impact of Adults on Adolescents’ Decision-Making. With funding from the U.S. Army, we are studying whether groups of late adolescents (18- and 19-year-olds) make better decisions when an adult is present than when an adult is not. This work should inform decisions about how soldiers are grouped together for combat missions.

Patterns of Development Among Juvenile Offenders

My work on patterns of development among juvenile offenders examines the factors that affect the development, behavior, and mental health of adolescents who have had contact with the justice system, and whether certain types of justice system responses are more likely to produce beneficial results than others.

Crossroads: Formal vs. Informal Processing in the Juvenile Justice System. In a collaboration with Elizabeth Cauffman, at the University of California, Irvine and Paul Frick, at the University of New Orleans, we are studying how diversion from formal processing by the justice system affects the subsequent behavior and development of first-time juvenile offenders. We are following samples of offenders for three years in Philadelphia, Santa Ana, and New Orleans (Jefferson Parish) who have committed similar offenses, but who have either been formally processed in court or diverted into a more informal arrangement, to study whether diversion leads to fewer disruptions in development and less recidivism. This project is funded by the MacArthur Foundation and the Office of Juvenile Justice and Delinquency Prevention.