True Nature: A Theory of Sexual Attraction. (Book reviews: is half an interactional theory still an interactional theory?).

True Nature: A Theory of Sexual Attraction. By Michael R. Kauth. New York: Kluwer Academic/Plenum Publishers, 2000, 250 pages. Cloth, $65.00.

Reviewed by Daryl Bem, Ph.D., Department of Psychology-Uris Hall, Cornell University, Ithaca, NY 14853; e-mail: [e-mail].

In True Nature, Michael Kauth seeks to provide an "interdisciplinary interactionist theory of sexual attraction that accounts for the interlocking sequence of biological and psychosocial developmental events, as well as the powerful influence of cultural beliefs, social practices, and institutions" (p. 5). The theory is thus designed to address both the ultimate and the proximate causes--the why and how, respectively--of sexual attractions. The first concerns the evolutionary roots of our species' sexual attractions; the second, the biological and psychosocial developmental roots of our individual sexual attractions.

The book is divided into six chapters. In the opening chapter, Kauth lists a number of objections to existing theories of sexual attraction. His first objection is that most of the older theories pathologize same-sex attraction and even contemporary theories that do hot pathologize still treat same-sex attraction as the only phenomenon requiring explanation. Opposite-sex attraction is simply assumed to be a given, the evolutionary consequence of reproductive advantage. Kauth's second objection is that most current theories address either the ultimate or the proximate set of causes but not both. Finally, Kauth objects that most theories are limited to discipline-specific factors and thereby fail to apprehend the interaction between biology and the social environment.

In Chapters 2 through 4, Kauth critically reviews past and current approaches to sexual attraction, evaluating them both conceptually and empirically. In Chapter 2, he discusses psychoanalytic and learning/conditioning approaches, as well as their technological offspring, the conversion therapies for "curing" homosexuality.

In Chapter 3, Kauth describes a simplified, radical version of the social constructionist position and then attempts to "salvage" (his word) a modified, more palatable version of it. He suggests that social constructionism "may function best as an investigational strategy to enhance scientific research. By giving more attention to the politics of scientific discourse, as constructionists suggest, scientists can better understand their subjects and constructed reality" (p. 108, italics in the original).

In Chapter 4, Kauth evaluates biological research on sexual attraction, including studies of prenatal hormones, pheromones, and the neuroanatomic and cognitive correlates of sexual orientation. He also discusses evolutionary theory and the genetics of sexual orientation. This chapter is the strongest in the book and could usefully be assigned to students in an introductory course on gender and sexuality.

In general, these three review chapters provide a reasonably complete and balanced presentation of the several approaches, their conceptual strengths and weaknesses, and the empirical research associated with them. The exposition, however, is written at the level of an introductory textbook and is unlikely to satisfy more knowledgeable or critical readers. By way of comparison, Stein's (1999) critical analyses of the same materials in The Mismeasure of Desire is conceptually far more sophisticated. Stein's Talmudic dissection of the empirical evidence is impressively incisive, and he provides a particularly clear exposition of what is at issue in the debate between essentialists and constructionists. In contrast, Kauth's discussion of that same debate borders on caricature.

Kauth presents his own theory in Chapter 5. Beginning with the evolutionary roots of sexual attractions, he proposes that sexual attraction is a heterozygous trait that comes in two versions--other-sex eroticism and same-sex eroticism. Both are evolutionary adaptations: other-sex erotic attraction because it facilitated female-male sexual contact and increased the likelihood of producing offspring who would survive to reproductive age, same-sex erotic attraction because it controlled intrasex conflict and facilitated same-sex alliances for both males and females. Moreover,

   having a capacity for both same-sex and other-sex erotic attraction permits
   the widest range of adaptive responses and optimal fitness in terms of
   reproductive advantage in unstable environments. Thus, on the average,
   individuals with a ratio of varied sexual attractions were better fit than
   individuals with an exclusive sexual attraction.... Neither form of
   exclusive sexual attraction is more common or more privileged than is the
   other, and neither form of exclusive attraction is optimal in a
   reproductive sense. (pp. 184, 186)

Oddly, Kauth then contradicts his claim that other-sex and same-sex eroticism are equivalent by asserting that the former is the dominant variant of the trait. Nevertheless, he is clear that the evolutionary process has left most members of our species with undifferentiated sexual attractions.

In the second part of Chapter 5, Kauth purports to address the problem of proximate causation: How do we get from the undifferentiated sexual-attraction genotype to individual differences in the sexual-attraction phenotype? He begins with the biological component of his interactional theory, prenatal sex hormones. In particular, he theorizes that the relative ratio of the hormones (low or high), their timing during gestation (early or late), and their duration (brief or long) combine to sensitize key neural structures to sex-typed stimuli and to predispose individuals to learn sex-specific erotic associations during postnatal development. He presents a table showing how particular combinations of these three variables produce four types of erotic predispositions: undifferentiated, other-sex, same-sex, and absence of sexual attraction.

It appears at this point in the exposition that Kauth is about to propose that prenatal hormones serve to predispose an individual toward particular sexual attractions and that the social environment subsequently serves to shape the phenotypic expression of that predisposition. But the theory suddenly takes an unexpected turn. Kauth notes that at the end of the prenatal period.

   most people are in the undifferentiated erotic categories, which represents
   a middle range of hormone exposure across dimensions .... In brief, the new
   model of sexual attraction purports [sic] that typical fetal hormone
   exposure lies in an average or middle range.... Most men and women
   experience an undifferentiated erotic predisposition and have the potential
   to experience erotic and sexual attraction to both sexes. (pp. 188, 191,
   italics in the original)

In other words, even after the prenatal hormones have "done their thing," most individuals remain undifferentiated with respect to sexual attractions. So we are still left with the original question of proximate causation: How do we get from the undifferentiated sexual-attraction genotype to individual differences in the sexual-attraction phenotype? Because the hypothesized biological factor does not serve to predispose most individuals toward sex-specific attractions, the answer must necessarily lie in the other component of Kauth's interactional theory: the social environment.

Kauth appears to concur. His short answer is that "cultural beliefs and social pressures guide sexual feelings and behavior in particular directions" (p. 191). His extended elaboration of this short answer, however, is virtually empty of empirical content. He does discuss how erotic stimuli in general might get processed and encoded in various parts of the brain, and he does make some banal cross-cultural observations: "For a majority of men in ancient Greece same-sex erotic attraction and sexual relationships were not only possible but also expected and even idealized ... Contemporary Western culture does not encourage same-sex eroticism, and not surprisingly, most men and women describe themselves as `heterosexual'" (p. 197). Nowhere, however, does Kauth spell out any specific psychological mechanisms, social processes, or developmental trajectories that would help us to predict an individual's sexual attractions. Although he briefly cites a couple of theories that attempt to do precisely that--including mine, alas--he dismisses them while offering nothing in their place.

In his concluding chapter, Kauth suggests a limited research program for testing the new model of sexual attraction. Among his suggestions are developing better measures of eroticism and sexual attraction, promoting cross-cultural studies, developing the technology for identifying erotic genotypes, and conducting long-term prospective studies that assess patterns of fetal hormone exposure and their consequences in later life. None of his suggestions, however, target any psychosocial developmental variables that might help us to predict an individual's sexual attractions. The reason is not far to seek: There are no such variables in Kauth's "interactional" model.

In addition to this major theoretical problem, Kauth's book contains a disquieting number of errors, conceptual and otherwise. For example, Kauth's discussion of Joseph Nicolosi's reparative therapy erroneously implies that it is based on principles of conditioning. In fact, however, it is premised on psychoanalytic claims about dysfunctional father-son relationships and is not an exemplar of behavioral therapy.

A surprisingly elementary error occurs in Kauth's discussion of genetic studies, in which he states that dizygotic twins share half of their genes but that ordinary siblings "share only 25% of their genetic material ..." (p. 135). This is incorrect. Like dizygotic twins, ordinary siblings also share approximately half of their genes; genetically, dizygotic twins are ordinary siblings.

Other errors in the book range from the trivial (e.g., I appear as David Bem in Chapter 1 and Daryl Bem elsewhere) to the potentially libelous: Kauth asserts that Joseph Nicolosi was dismissed from membership in the American Psychological Association for antigay and unethical clinical practices in conversion therapy. I could find no record that this is true and believe that Kauth is confusing Nicolosi with the antigay psychologist and activist Paul Cameron, who was dismissed for undisclosed violations of the APA Code of Ethics.

A metaphysical question: Is half an interactional theory still an interactional theory?

REFERENCES

Stein, E. (1999). The mismeasure of desire: The science, theory, and ethics of sexual orientation. New York: Oxford University Press.