It was praised as a well-written discussion of science that properly acknowledged the limitations of genetic research on homosexuality, usefully explored its ethical implications, and drew on a wide range of sources and publications.

However, reviewers were unconvinced by Hamer's suggestions about the possible evolutionary basis of homosexuality, and argued that some of his claims were incorrect, that more work needed to be done to confirm or refute his genetic findings, and that his use of the term "gay gene" was misleading.

According to Hamer, he shifted his area of research from metallothionein to the genetics of homosexuality after reading the naturalist Charles Darwin's The Descent of Man, and Selection in Relation to Sex (1871) and the evolutionary geneticist Richard Lewontin, the neurobiologist Steven Rose and the psychologist Leon Kamin's Not in Our Genes (1984).

She credited Hamer with carefully pointing out the limitations of genetic research on sexual orientation, simplifying complex ideas for general readers, and exploring the ethical implications of a "gay gene" with "laudable compassion and common sense.

[4] Angier described the book as "a surprising delight to read", writing that Hamer did not overstate his case for the innateness of sexual orientation and "has the welcome habit of sticking to the facts."

He credited Hamer with avoiding over-stating the importance of his work or sensationalizing his results, writing that he had produced a "clear and capable book about a difficult subject.

[9] Lener wrote that parts of the book were "diary-like", and gave Hamer's "descriptions of methods used" and "life histories of gay men who participated in the study" as examples.

"[10] Gonsiorek considered the book a competent and engaging discussion of Hamer's scientific work, but one that showed the "tension and unease" inherent in popularizing science.

He called Hamer's discussion of the development of his research protocol "gossipy" and wrote that it contained "many tidbits, some less than kind, and many less than relevant" about the people involved.

He praised Hamer's "ability to synthesize information from diverse sources and apply it creatively", his discussions of possible biological mechanisms for the heritability of male homosexuality and the public policy implications of his scientific research, and his criticism of social constructionism.

He concluded that while Hamer's work "presents technical and conceptual difficulties" and his "preliminary findings obviously need replication or refutation" it "represents a genuine epistemological break away from the past's rigid and withered conceptions of sexual preference.