The theory that some male homosexuals might have female chromosomal constitution (Lang, 1940) became untenable when techniques for studying sex chromosomes were developed. Amongst others the work of Pare (1956) and Raboch and Nedoma (1958) showed that male homosexuals had normal male chromosomes. The latter authors in the same study also reported on 36 male patients with a female type of sex chromatin (i.e. chromatin positive) and could not detect any homosexual orientation: 32 were definitely heterosexual and the remaining 4 were considered ‘infantile’, They assumed that the finding of a chromatin-positive homosexual would be coincidental and that there was no causal relationship between this sex chromosome abnormality and homosexuality. Money and Pollitt (1964) searched for a genotypical abnormality in a related psychosexual disorder, namely transsexualism, but although they collected six cases in the literature where Klinefelter's syndrome and transsexualism occurred together, the correlation was not statistically significant. In fact, it would now appear to be established that there is no specific correlation between sex chromosome abnormality and psychosexual disorders (Slater and Cowie, 1971).