Jerome Kagan is a contemporary psychologist whose research has helped widen the field of developmental psychology.

Professional Life

Jerome Kagan was born in Newark, New Jersey in 1929. He was influenced by his grandfather's interest in human psychology to pursue the field, and he earned his bachelor’s from Rutgers in 1950. Kagan went on to Yale where he received his PhD in psychology in 1954.

Kagan worked briefly as a psychology instructor at Ohio State University, in 1954, before being recruited to work in the US Army Hospital during the Korean War, between 1955 and 1957. Next, he was hired as a researcher in developmental psychology at the Fels Institute in Ohio, where he worked until 1964. He was concurrently an associate professor of psychology at Antioch College beginning in 1959. He later became the head of the Psychology Department at the institute. Kagan accepted a professorship from Harvard in 1964, where he remained until his retirement in 2005.

Kagan received the Hofheimer Prize in 1963 from the American Psychiatric Association, the Distinguished Scientist Award in 1987, and the G. Stanley Hall Award in 1995 from the American Psychological Association. Kagan has authored and co-authored many books on the temperament and emotional development of children. He is considered one of the most influential psychologists of the 20th century.

Contribution to Psychology

Kagan spent a large part of his career studying the effect of temperament— a stable pattern of personality and emotional reactions —on the behavior of children. Behaviorism was popular at the beginning of Kagan's career, but Kagan's research led him to believe that environment wasn't the sole determining factor of a child's personality, and he began to examine the influence of biological factors. He followed his test subjects from infancy through adulthood, evaluating specific traits at different periods. His first book revealing his research was Birth to Maturity, published in 1962 with Kagan’s colleague Howard Moss.

Kagan was able to assess unique personality traits by examining children over time. In one study, he found that a child's earliest experiences prior to the age of three didn't have much relationship to her adult personality, whereas anxious, inhibited babies tended to grow into anxious, inhibited adults. While Kagan emphasized the role of biology in the development of temperament, his work points to a combination of biological and environmental factors; the two are not easily separated. Kagan determined that the first two years of a child’s life are critical in the development of self-consciousness, memory, sense of morality, and symbolism.

Kagan studied how biological conditionals increased a child’s vulnerability to emotions, like fear and apprehension. His theory of emotion grew out of his research on temperament. He posited that emotion is the result of specific brain states combined with context and temperament. He also pointed out that self-reports of emotions might not be reliable. Instead, Kagan advocated that words used to describe emotions should be clear and not open to subjective interpretation. For example, a researcher examining emotion might ask participants about the specific physiological states they are experiencing rather than simply asking about a specific emotion. In 2007, Kagan published the book What Is Emotion? History, Measures, and Meanings.

Books by Jerome Kagan:

  • Understanding Children: Behavior, Motives, and Thought (1971)
  • Growth of the Child (1978)
  • The Family (1978)
  • The Second Year: The Emergence of Self-Awareness (1981)
  • The Nature of the Child (1984, 1994)
  • Unstable Ideas: Temperament, Cognition, and Self (1989)
  • Three Seductive Ideas (1998)
  • Surprise, Uncertainty, and Mental Structures (2002)
  • An Argument for Mind (2006)
  • Psychology’s Ghosts: The Crisis in the Profession and the Way Back (2012)
  • The Human Spark: The Science of Human Development (2013)


  1. Jerome Kagan. (n.d.). New England Complex Systems Institute. Retrieved from
  2. Jerome Kagan. (2008). Contemporary Authors Online. Biography In Context. Retrieved from