While the differences in the incidence of postpuberal masturbation among the various groups are small (the range is only 92—100 per cent), it is significant that the incest offenders vs. adults—who are, as we have pointed out, the most sexually restrained of our groups-provide the 92 per cent figure. The unmarried men uniformly have the smallest age-specific incidence figures. Between puberty and age fifteen, when 13 of our comparative groups reported that 80 per cent or more of their constituents had been masturbating, and eight groups reported 90 per cent or more, these incest offenders reported only 71 per cent. In age-period 21—25 they were the only group of whom less than half had masturbated. While small sample size restricts our study of age-specific incidence of masturbation among married incest offenders vs. adults, it appears that these incidences are definitely low—and much lower than those of the control group. This minimal masturbatory picture is also illustrated in an examination of the maximum frequencies of masturbation: not one incest offender vs. adults had masturbated more than a dozen times in any week of his life. Every other group, offender or control, had some individuals who had exceeded 12 times. Some 48 per cent (the second highest percentage) had never masturbated more than once to twice a week. Within this frequency category the incest offenders rank second, third, and fifth; in brief, they are all characterized by low maximal frequencies.
The incest offenders vs. adults are similar to the other incest offenders in having masturbated relatively infrequently during their premarital lives. The average (median) incest offender vs. adults always is found in the lower third or even quarter of rank-orders with masturbatory frequencies of 2 or 3 times a month. In mean frequencies the members of this group are even more restrained: they are at the bottom of the rank-order until age twenty and next to the bottom in age-period 21-25 which represents the chronological limit of our data for them. For a group to show such restraint in regard to masturbation, as well as in their heterosexual and homosexual behavior, is most unusual.
Low incidence of masturbation plus smallness of sample size make it impossible to calculate meaningful frequencies for the married incest offenders vs. adults.
Although the masturbation frequencies before marriage were low, so were the frequencies of their other sexual outlets, with the result that in their early teens these offenders derived 82 per cent of all their orgasms from masturbation, the second largest proportion recorded for that age-period. Thereafter, among the unmarried, the proportion is moderate and essentially the same as that of the control group. Among the married the proportions are usually small and often the smallest manifested by any group according to our limited data.
The incest offenders vs. adults began to masturbate later than the members of any other group, the median age after puberty being nearly fifteen years. However, one must bear in mind that these particular offenders also attained puberty later than any others, and their “late start” may simply reflect this fact.
Resembling the other incest offenders, who rarely had homosexual fantasy while masturbating, no incest offender vs. adults reported such fantasy. They are, as we shall confirm later, the least homosexual of any group. Aside from homosexual fantasy, the incest offenders vs. adults display a tendency toward a diversity of fantasy, ranking fourth in sadomasochistic fantasy (7 per cent), third in fantasy of animal contact (7 per cent), and fifth (14 per cent) in bizarre fantasy. On the other hand, 12 per cent never fantasied—a fairly large percentage compared with other sex offenders, though similar to the percentage reported by the control group.
Comparison of this fantasy record with the conscious response to various stimuli reveals various parallels. The minimal amount of homosexual fantasy is in accord with the tiny percentage (4 per cent) of men who reported some sexual arousal from thinking of or seeing other males and the absence of any who claimed a strong arousal. Similarly, the fairly large number who never fantasied agrees with the fairly large number (25 per cent) who claimed to have been never or seldom aroused by thinking of or seeing females and the very small number who found strong arousal from this stimulus.
While the incest offenders vs. adults had little masturbatory experience, they worried about it more than any other group. This is in keeping with their general restraint and feelings of guilt. Concern over masturbation does not characterize incest offenders as a whole: the incest offenders vs. minors, it may be recalled, had the least worry of all.
In the matter of the source of knowledge of masturbation, the incest offenders vs. adults display a low percentage (9 per cent) who learned by being masturbated by another individual. This finding might have been anticipated since they had very little prepubertal sex play and, moreover, did not socialize well with other children at ages ten to eleven. It is somewhat puzzling, therefore, that only another 9 per cent learned through self-discovery. As is typical of incest offenders, a large proportion (36 per cent, the second largest percentage) learned of masturbation chiefly from talking or reading.