What Makes Each of Us Who We Are?

Book cover and Jay Belsky headshot

“‘The Origins of You’ poses a question that is both timely and timeless: How does each of us become the unique person we are? Drawing upon the most authoritative psychological studies ever conducted on the topic, the authors offer a treasure trove of remarkable insights that both underscore the complexity of human development and affirm the power of human resilience.” ― Dan P. McAdams, author of “The Art and Science of Personality Development”


Four researchers, including Professor Jay Belsky of the UC Davis Department of Human Ecology, share their insights from three long-term studies following large numbers of people from as young as birth to as old as middle age.

“The result is unprecedented insight into what makes each of us who we are,” the publisher declares in describing the book.

The description lists some of the researchers’ questions: “Does temperament in childhood predict adult personality? What role do parents play in shaping how a child matures? Is day care bad ― or good ― for children? Does adolescent delinquency forecast a life of crime? Do genes influence success in life? Is health in adulthood shaped by childhood experiences?”

Belsky did the writing. He drew on his work studying American children from birth to age 15 — addressing the effects of day care on child development, the experience of being parented as a child on how one parents as an adult, and the effect of adverse childhood experiences on girl’s physical maturation and sexual behavior — and his co-authors’ work in New Zealand and the United Kingdom.

Here is some of what The Origins of You reveals, according to Belsky:

  • Disruptive 3-year olds are at high risk of engaging in criminal behavior in adolescence and adulthood.
  • Adverse childhood experiences can lead girls to mature physically earlier than would otherwise be the case.
  • Bullying in childhood predicts obesity later on.
  • And, extremely important, the realization that each of these risks is not inevitable. By illuminating if, when and how risks such as these are — or are not — realized, Origins offers its readers insight into the mystery and magic of human development.

The book seeks not only to advance knowledge about human development, Belsky said, but to engage readers in the research process itself, thereby helping them think about human development in a more sophisticated way than is often the case (i.e., not just nature or nurture; not just parent or peer influence; not just family or day care effects).

The co-authors

  • Jay Belsky is the Robert M. and Natalie Reid Dorn Endowed Chair Professor in Human Development and Family Studies. He was a founding investigator of the Study of Early Child Care and Youth Development in the United States (study sponsored by the National Institute of Child Health and Human Development, National Institutes of Health), and the National Evaluation of Sure Start in the United Kingdom. He is a recipient of the Urie Bronfenbrenner Award from the American Psychological Association.
  • Avshalom Caspi is the Edward M. Arnett Professor of Psychology and Neuroscience at Duke University and professor of personality development at King’s College London. He is a recipient of the American Psychological Association Award for Distinguished Scientific Contributions to Psychology.
  • Terrie Moffitt is the Nannerl O. Keohane University Professor at Duke University and professor of social behavior and development at King’s College London. She has received a host of honors, including the Stockholm Prize in Criminology, and is a member of the National Academy of Medicine.
  • Richie Poulton is a professor of psychology at the University of Otago (New Zealand), where he serves as co-director of the National Centre for Lifecourse Research. An elected fellow of the Royal Society of New Zealand, he received the New Zealand Prime Minister’s Science Prize for the Dunedin Multidisciplinary Health and Development Study.

Leigh Houck is a June 2020 graduate of UC Davis — Spanish literature major, writing minor — who works as in intern for the News and Media Relations Team in the Office of Strategic Communications.

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