<< Onset of Sexual Activity >>

Any consideration of the age of onset of adolescence is made difficult by the fact that there is no single criterion by which that age can be recognized. In Chapter 5, in presenting the statistical data on adolescent developments, it was pointed out that there are a good many physical characters involved, and that they do not all appear and develop at exactly the same time. In the same chapter, it was pointed out that the designation of a particular year, in any individual’s history, as the age of onset of adolescence, must, therefore, depend upon judgments which may sometimes be arbitrary and not exactly in accord with all of the details of the fact.

In the present study, the time of onset of adolescence has been fixed as the date of the first ejaculation, unless there has been evidence that ejaculation would have been possible at an earlier age if the individual had been stimulated to the point of orgasm. When the year of first ejaculation coincides with the year in which the first pubic hair appears, and with the time of onset of rapid growth in height, and/or with certain other developments, there is no question that that year may be accepted as the first year of adolescence. Eighty-five per cent of all male histories fall into this category. On the other hand, if the first ejaculation follows these other events by a year or more, and if it is clear that there was no test of the individual’s sexual capacity prior to the first ejaculation, and if there seems to be no question of the reliability of the memory in regard to the dates of the other adolescent developments, then the age of onset of adolescence is better established by events other than ejaculation. Where first ejaculation occurs as a nocturnal emission, it usually (though not always) does not come until a year or more after the appearance of the other adolescent developments, and the onset of adolescence should be set a year or more before the first ejaculation.

To define the time of onset of adolescence by any single criterion does not satisfy the reality as well as a judgment based on all of the pertinent data. Even hormones and the 17-ketosteroids cannot be accepted as the sole criteria for determining this event, or any other event. The history of systematic botany and systematic zoology is replete with attempts to discover significant and diagnostic characters which might provide clear-cut and absolute bases for systems of classification; but the modern taxonomist finds that the use of a single character inevitably provides a classificatory system which is artificial and, at least at certain points, in direct conflict with data from other sources. Every aspect of a situation is part of the reality which one must take into account, if one is to understand that reality. In the present instance, the onset of adolescence must be recognized whenever there is any development of any physiologic or physical character that pertains to adolescence. The ages of onset of adolescence used for statistical analyses in the present chapter, and throughout this whole volume, are based upon this use of the multiple characters which are concerned.

The use of multiple characters in a taxonomic classification inevitably calls for a certain exercise of subjective judgment, and this is the most serious objection to such a procedure; but the errors introduced by judgment are not likely to be as misleading as the artificialities introduced by the use of a single set of criteria in a classification.

In this study, the determination of the age of onset of adolescence has been further complicated by the necessity for depending on the subject’s memory for a report of what is supposed to have happened. Considering the indefinite nature of the event itself, and this difficulty of obtaining accurate records by way of memory, it is surprising that it has been possible to demonstrate correlations between this phenomenon and any aspects of sexual behavior.

It will be recalled that the average age of onset of adolescence for the white male population has been calculated as 13 years and 7 months (Chapter 5). There are very few boys who reach adolescence prior to age 10, and few even before age 11. Consequently, in most of the tables accompanying the present chapter, the males who were adolescent prior to age 11 have, for purposes of calculation, been included in one group with those who began adolescence at 11. In a few instances, the small number of available cases has made it necessary to put all those adolescent before 12 into the 12-year group. Those who were adolescent after age 15 are grouped with those who became adolescent at 15.

In order to make significant comparisons, it has been necessary to confine the analyses to groups that are homogeneous for sex, race, marital status, and educational level, as well as for the age of onset of adolescence. The tables in the present chapter cover all of those segments of the population which are now represented in the sample by enough cases to warrant statistical treatment. There has been no other basis for selecting the groups which are included.

The first difference to be observed between the males who become adolescent at an earlier age, and the males who become adolescent at an older age, is the fact that the younger-adolescent boys begin regular sexual activity of some sort, and begin having a regular outlet, more or less coincidently with the onset of adolescence. Some of them, as a matter of fact, had already experienced regular orgasm in pre-adolescence. On the other hand, the older-adolescent males, despite the fact that they have taken four or five years more in reaching adolescence, often delay a year or two beyond that before they ejaculate for the first time. Sometimes it is still longer before they acquire anything like regular rates of outlet. Early-adolescent males ejaculate in the same year in which they become adolescent in 92 to 100 per cent of the cases (Table 67). The older-adolescent males ejaculate in their first year of adolescence in only about 80 per cent of the cases. Nearly every one (99.5%) of the younger-maturing boys acquires a regular sexual outlet between the time of adolescence and age 15.

Table 67. Lapse between onset of adolescence and first ejaculation
Date of First
Ejaculation		 Age of Onset of Adolescence
Before
  10  		   10     11     12     13     14     15     16  
%
Same year 100 96 92 87 83 78 78 81
Second year 0 2 5 8 11 14 16 11
Third year 0 0 2 3 3 5 4 5
Fourth year 0 2 1 1 1 2 2 3
Still later 0 0 0 1 2 1 1 0
Cases 14 94 309 1059 1510 1233 307 80

There is an interesting correlation of the source of first ejaculation and the age of onset of ejaculation (Table 68, Figure 89). For the boys who become adolescent by 11 years of age, masturbation provides the first ejaculation in nearly three-quarters of the cases (71.6 per cent); but for the boys who become adolescent last, masturbation is the source of the first outlet in only about half of the cases (52.1 per cent). Nocturnal dreams, on the contrary, are the first source for only 21.6 per cent of the younger-adolescent boys, but for 37.1 per cent of the late-adolescent males. The boys who mature first more often act deliberately in going after their first outlet; the boys who mature last more often depend upon the involuntary reactions which bring nocturnal emissions.

Table 68. Sources of first ejaculation in relation to age at onset of adolescence
Source of First Ejaculation Percent Depending on Each Source
when age at onset of adolescence is:
8-11 12 13 14 15+
Masturbation 71.6 64.8 58.9 55.0 52.1
Nocturnal emissions 21.6 28.2 35.6 38.9 37.1
Petting 0.0 0.3 0.6 0.3 2.2
Intercourse 0.6 1.4 0.9 0.9 3.2
Homosexual 2.6 3.2 1.2 2.0 2.2
Animal 0.3 0.3 0.2 0.3 0.0
Spontaneous 3.3 1.8 2.6 2.6 3.2
Total 100.0 100.0 100.0 100.0 100.0
Cases 306 722 984 650 186
Figure 89. Sources of first ejaculation in relation to age at onset of adolescence

The sexual activities of these boys who start the earliest are far from incidental. Between adolescence and 15 years, their rates are higher than the rates of any other group of single males, of any age, in any segment of the white population. Consequent on their quicker start, there are 16 per cent more of the early-adolescent boys than there are of the late-adolescent boys, who are active between adolescence and 15. Early-adolescent boys have four or five years in which to make a start in that period, while the later-adolescent boys have only one year in the period; but the higher incidence of activity among the early-adolescent boys must depend, in part, upon the generally higher level of performance in the group. This is confirmed by the fact that in all subsequent age periods there is still a slight but consistent difference in incidence in favor of the boys who became adolescent earliest.

>>