Eve's Rib: The Biological Roots of Sex Differences

An eye-opening overview of current biological research in the field of gender differences discusses the implications of scientific discoveries for the roles of men and women in society. 15,000 first printing.

Few would dispute that behavioral differences distinguish the sexes; the question remains whether nature or nurture causes the differences. Are women more "nurturing" than men because of their hormones, or are they responding to what they have been taught? Is aggression in men due mainly to testosterone? Pool takes pains to emphasize that the "differences do not imply that one sex or the other is superior--instead the scientists see men and women as inherently equal." This book--Pool's first--explores the subject by seeking out the scientists--most of whom are women--now doing the research. He refutes the idea that either nature or nurture is solely responsible: "None of the sex differences is completely fixed by biology . . . the most it can do is establish predispositions that interact with the environment to create a person. . . . Hormones may push males and females in different directions, but society can either exaggerate or dampen these differences, depending on how we teach our children and what we expect of ourselves." Pool's foray into the complex scientific world of sex differences is not a dry treatise. His book is an entertaining narration of current research into the mental, emotional and psychological differences between men and women. It may not end verbal sparring between the sexes, but it will provide each side with some intriguing ammunition.
Copyright 1994 Reed Business Information, Inc.

Through shrewdly selected examples and engaging interviews with researchers, science journalist Pool (Science, Discover, Nature, etc.) assembles a convincing argument to explain the biological basis of sexual differences. Wisely limiting himself, Pool considers the role of hormones in prenatal development: While all fetuses begin as female, the male is differentiated by an infusion of testosterone that alters both the structure of the brain and its function. For biological reasons, then, he claims, boys really do prefer trucks and girls dolls. Boys have a better spatial sense, stronger competitive instincts, and a preference for objects, whereas girls demonstrate greater verbal ability, a more cooperative nature, and an interest in people. Moreover, faced with the same problems, boys and girls use different parts of the brain to solve them and at different speeds: While both can get out of a maze, girls look for landmarks but boys prefer maps. Physiologically, while the male brain is larger, it is not necessarily superior. Of course, there are variations: girls with excess testosterone; boys with excess estrogen; chemicals such as DES that effect pregnancies; and changes in the hormone levels throughout life. All of these biological events, according to Pool, influence behavior far more than the socialization process to which feminists especially have attributed the sexual stereotypes that they want to overturn. Ironically, it was women, often feminists, who made the discoveries about the biological bases of sexual differences. In a speculative chapter, Pool concludes that these differences evolved to suit a more primitive culture and are no longer relevant or useful. A convincing and optimistic study promoting the advantages of difference, the futility of influencing the environment of young children to produce people who are the same but not necessarily equal. Pool captures the resourcefulness of the researchers, the voices of those who made the discoveries and tested them in their own lives. -- Copyright ©1994, Kirkus Associates, LP. All rights reserved.

Few people would oppose equal opportunity for men and women, but Eve's Rib offers compelling evidence that it may be unrealistic to expect an equal outcome. Results of multidiscipline experiments as well as serendipitous findings lead Pool to conclude that the hormonal environment (principally, testosterone level) in the womb launches fetal brain development down either a distinctively male or female path, which is expressed in gender-specific preferences for childhood activities. Other studies indicate that at critical stages of maturation, hormones continue to communicate with the cerebral cortex to further develop gender-biased thought processing, resulting in a hierarchy of cognitive aptitudes and social strategies that propels the child along the road to adeptness in either traditionally masculine or feminine pursuits. Pool suggests, however, that although hormones configure predispositions, society may amplify or moderate these tendencies, and that it is the interaction with the environment that creates a person. Brenda Grazis

Pool is a journalist/editor who has published in several prestigious scientific journals. Here, he chronicles controversial and complex research into gender differences, examining chromosomal and hormonal influences on anatomical and psychological sexual development, pre-and postnatal environmental influences, distinctions in brain anatomy, behavioral differences, and the emotional debate surrounding the research. His explanations are clear, well referenced, and replete with examples. His philosophical arguments are weakest when addressing human society, suggesting that self-selection may be the primary reason for disparities in human occupational choices. In this regard, Pool might have benefited from examining Sue V. Rosser's Biology and Feminism (Twayne, 1993), which discusses the implications of women penetrating a science of male-crafted theories. Pool's meanderings into personal accounts of researchers and his family are occasionally insightful but often distracting. Still, this thorough and generally balanced account should convince readers that a biological foundation for sex differences exists, with positive ramifications. Highly recommended.
Constance Rinaldo, Dartmouth Coll., Hanover, N.H.
Copyright 1994 Reed Business Information, Inc.