To The Nurture Assumption home page
(published by the New Jersey Association of Cognitive-Behavioral Therapists)
Copyright 1999 by Milton C. Spett.
Posted with the author's permission.
On November 19, Judith Rich Harris, author of The Nurture Assumption, the nationally acclaimed runner-up for the Pulitzer Prize, led ACT's first Friday evening workshop. Harris's Group Socialization Theory asserts that half of adult personality is determined by heredity and the other half is determined by the child's peer group. A second key tenet of Harris's theory is that behavior is context-specific: behavior that is learned in one context, such as the family, does not generalize to other contexts.
In my original critique of her book, I pointed out that Harris cited no controlled research supporting her assertion that children's peer groups are an important determinant of the child's adult personality. As Harris stated in her ACT workshop, however, Dishion's article in the September, 1999 American Psychologist reported two studies in which group interventions with anti-social adolescents had negative effects, including increased alcoholism and arrests, many years later. Dishion concluded that the adolescents' interactions with each other reinforced their anti-social behavior, overwhelming the group leaders' efforts to instill prosocial behavior. Based on this type of research and her theory, Harris cautioned against any group interventions with anti-social patients.
Harris also asserted that parent training programs may improve the child's behavior within the family, but will have no effect on the child's behavior in any other context. This position is in direct opposition to Gerald Patterson, the dominant theorist in the field of treating oppositional and conduct disordered children. Patterson holds that child anti-social behavior is caused by coercive parenting, and interventions should be addressed to the parents of the anti-social child. Harris argues that Patterson's theory is widely assumed to be correct, but there is not one shred of evidence supporting it.
Harris differentiated her theory from Walter Mischel's theory that behavior is situation specific. Mischel's theory fell into some disrepute because research found that individuals do demonstrate some behavioral consistencies across situations. But Harris points out that these behavioral consistencies are due to genetic factors, which Mischel did not include in his theory.
Finally, Harris argued that birth order effects do not influence behavior outside of the family. The observation that first children tend to be high achievers is an artifact of SES. Since high SES parents tend to have fewer children, a larger percentage of first children come from high SES families.
I personally found Harris's presentation to be both delightful and scientifically impeccable. Her talk was followed by thunderous applause, which is not easy from an audience of fifteen. Her theory annoys developmental psychologists, but as Harris points out, "That is good. One of my main goals in life is to annoy developmental psychologists."
Milton Spett, Ph.D., is a licensed psychologist with a private practice in Cranford, New Jersey.