I.D.

An unwieldy assemblage of information on the varied elements- -from genes to neurotransmitters to early life experiences—that are believed to contribute to personality. Science writer Gallagher (The Power of Place, 1993) has assembled but not digested a huge amount of information on the complementary roles of nature and nurture in forming our individual identities. Her book centers on a woman identified as Monica. Monica was studied from her sensually deprived infancy (when an esophageal defect necessitated tube feeding and a depressed mother neglected her) and on into her unpredictably happy, successful adulthood—a success psychologists say is due to an inborn temperamental gift that we might call charisma. Pursuing this and many other studies (but without sourcing them), Gallagher brings out a particularly interesting point: that research has found nature and nurture to be linked in a two-way relationship. For instance, experience can actually change neurotransmitter patterns in the brain; conversely, our inborn temperament can influence what kinds of experiences we have. But Gallagher lacks a strong framework or point of view; she roams all over the psychological map, from memory to the unconscious to the artistic temperament. Too often, she gives an on-the-one-hand/on-the-other summary of the facts that leads to no conclusion other than the fairly useless one often repeated to her by researchers: We still don't know how much our genes and our environment contribute respectively to our selves. Further, she relies heavily on models that measure temperament on a range of axes, such as extroversion and agreeableness. But while Gallagher protests how complex personality is, this theory sounds like a simplistic building-block approach: Mr. X may have a large dose of extroversion, a touch of irritability, etc. Researchers recently announced the identification of a gene they say influences temperament. Only the future will tell us what Gallagher unfortunately can't.