Perv: The Sexual Deviant in All of Us by Jesse Bering -book review: 'Mind-boggling tour through human sexuality'

Early on in his fascinating book about human sexuality, Jesse Bering, a previous university psychology professor, tells us that the word "pervert" used to mean atheist. In the past couple of hundred years it has come to mean a sexual deviant. But what an emotionally loaded word it is, carrying as it does the weight of labels of "normality" and "abnormality", stigmatisation, the shrieking moral brigade/religious right wing, and even medicalisation of sexual preferences. Bering's favoured approach is to ask if people's sexual behaviour causes harm to themselves or others, stressing that one person's idea of harm may not be another's.

There are many scintillating snippets of information in this book. One is the role of childhood imprinting in adult sexuality. In animal experiments, baby male rats suckled by a mother who had lemon scent on her teats, grew up to only be able to get aroused by and ejaculate with female rats who smelled citrusy. In another experiment, baby sheep and goats were switched at birth so that the baby sheep were raised by goats and vice versa. At adulthood, the male animals only showed sexual interest in their adoptive species. The female animals, however, showed interest in both, thus displaying a fluidity of sexual response that has also been shown in some human studies.

Bering does not steer clear of controversy. He cites work showing that in countries where child pornography is freely available, sexual offending against children is lower than in countries where child porn is not available. His recommendations here are contentious to say the least. Another area where this reviewer differed with Bering was where he uses cultural relativity to exonerate customs like those of the tribe in Papua New Guinea where it is customary for boys from the age of eight upwards to fellate the old men of the tribe daily. His assertion that there is no harm here because it is normal practice is assumption. He later condemns clitoridectomies in the West, but does not mention female genital mutilation in Islamic countries: by his own criteria, this would not be culturally out of place, but could he argue that it is therefore not harmful?

Bering's journey through the various paraphilias (unconventional sexual attractions) is as mind-boggling as it is informative. Who would guess that the German man convicted of killing and eating a victim would not meet the latest Diagnostic and Statistical Manual of Mental Disorders' criteria for sadism since his victim was willing?