The problem of obtaining reliable data is even more difficult. Adults can be asked about their sexual preferences by means of a confidential questionnaire. Or inferences can be drawn about the sexual tastes of those whose behaviour leads them to court appearances for paedophilic offences. Or we ran be guided by the professional experience of the psychiatrists to whom paedophiles go for 'treatment'.

None of these methods, or any others I have seen discussed, is at all satisfactory, for a variety of reasons. In particular, it cannot be over-emphasised that criminal statistics are misleading: a high percentage of those convicted of sexual offences involving children are not 'classic' paedophiles, i.e. they prefer an adult partner. In addition, only a small proportion of paedophiles have relationships which surface in the law courts. 

Of the practising paedophiles interviewed by Rossman, only 1 per cent had ever been arrested (Parker Rossman, Sexual Experience Between Men and Boys, p. 13). 

Dr Edward Brongersma has written, 'In a recently published French study, 129 men (average age 34 years) said they had had sexual contact with a total of 11,007 boys (an average of 85 different boys per man). The laws which make such contact criminal are thus in practice ineffective. This enormously high dark number shows that the law has degenerated to pure arbitrariness against a few unlucky individuals. According to the French study, only one in three thousand punishable acts comes to the knowledge of the police' (E. Brongersma, The legal status of the paedophile', paper presented to the Psychiatric-Juridical Society, Amsterdam, 1977).

Reports from adults on sexual contacts made in their own childhood may give a reasonable guide to the extent of paedophilic activity, although they do not (because of the possibility of multiple contacts by any adult) give much idea as to the total number of paedophiles. 

In response to an inquiry conducted among students at Nijmegen Catholic University in Holland, 13 per cent of the boys and 18 per cent of the girls reported that, as children, they had had at least one sexual contact with an adult (reported in 'The unknown paedophile' by Edward Brongersma). 

Kinsey had data from 4,441 women, of whom 24 per cent reported that they had been approached while they were pre-adolescent by adult males who appeared to be making sexual advances, or who had made sexual contacts with them. Half of these cases (.52 per cent) were of exhibitionism by the adult, and less than a quarter (22 percent) resulted in specifically genital contact with the child. 

At the University of California, 30 per cent of the male and 35 percent of the female students reported having had, as children, sexual relations with adults (J. Landis, 'Experience of 500 children with adult sexual deviation').

Parker Rossman (op. cit., p. 12) estimated that there are at least a million American men who since age 21 have been involved in one or more sex acts with young teen-age boys' and he added 'There are at least another half million males over age 21 in the United States who value sex play with boys and believe it should not be against the law, and who will on one or more occasions in the future be involved with teen-age boys in illegal sex acts.' He does not, however, state how these figures have been derived. 

The criminal statistics for England and Wales do not make any distinction between adult and child victims' for the offence of indecent assault, but the recent Home Office Research Unit study by R. Walmsley and K. White (Sexual Offences, Consent and Sentencing, Home Office Research Study No.54, HMSO, London, 1979, pp.30-32) found that in the year under study (1973) 88 per cent of male partners/ victims and about 70 per cent of female partners/victims in cases of indecent assault were under sixteen. In this year, 802 persons (8 of them female) were convicted of indecent assault on a male, and 3,006 (6 of them female) were convicted of indecent assault on a female.