The Third Culture

BIRTH ORDER AND THE NURTURE MISASSUMPTION: A Reply To Judith Harris
by Frank Sulloway [6.17.98]

[Editor's Note: See "How Is Personality Formed?" A Talk with Frank J. Sulloway - and also the response by Judith Rich Harris in The Reality Club.


INTRODUCTION

It is odd to find myself being criticized by Judith Harris in her commentary on my EDGE interview with John Brockman. This is because we share so much in common in our views about the origins of personality. For example, we agree that parents have relatively little direct impact on the personalities of their children. We also agree that genetics accounts for a substantial source of personality differences among human beings.

Where Harris and I disagree is over the nature of the specific environmental influences that are important in personality development. Harris ascribes these environmental sources almost entirely to the peer group--that is, to influences operating outside of the family environment. In particular, she contends in her book The Nurture Assumption that the influence of parents ends with conception. By contrast, I believe that a variety of influences, both inside and outside of the family, contribute to individual differences in personality. In this connection, I certainly support Harris's thesis that peer groups affect personality, and I applaud her constructive arguments on this topic. However, I also believe that Harris has pushed her thesis much too far, and that her rather extreme stand on this subject has led her to deny solid evidence in favor of within-family influences.

Much of the relevant evidence on within-family influences was presented in my recent book Born to Rebel: Birth Order, Family Dynamics, and Creative Lives. Based on 26 years of research involving 6,566 participants in 121 radical revolutions and reform movements, I demonstrated that birth order and other aspects of family niches are systematically related to personality for a variety of different traits. Furthermore, these behavioral findings hold when the data are controlled for sibship size, social class, and various other background influences that have tended to confound the results of previous studies on this subject.

The Reply Continued...