5. Results A

Go to >	A. Definitions of CSA, Prevalence Rates, and Types of CSA	29
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A. Definitions of CSA, Prevalence Rates, and Types of CSA

Definitions.

Definitions of CSA varied from one study to the next (see the Appendix ).

Most studies (70%) defined sexual experiences to be CSA if a sizable age discrepancy existed between the child or adolescent and other person, regardless of the younger person's willingness to participate;

20% of the studies restricted their definition of CSA to unwanted sexual experiences only.

Most studies (73%) defined CSA to include both contact and noncontact (e.g., exhibitionism) sexual experiences;

24% restricted their definition to contact experiences only.

Most studies (88%) reported specific upper age limits for children or adolescents in defining CSA. Of these studies,

most (75%) focused on middle to later adolescence with the oldest includable age for "child" usually being 16 (35%) or 17 (25%);

a minority of these studies (25%) included only experiences that occurred when participants were younger than 14 or were prepubescent.

Regarding age discrepancy, more than half of the studies (59%) defined sexual experiences with someone at least 5 years older to be CSA. This criterion generally applied to experiences that occurred when participants were less than 12 or 13.

About a quarter of the studies (27%) also defined adolescent sexual experiences with someone at least 10 years older to be CSA.

Others (17%) specified experiences with an adult, an authority figure, someone over 16, or someone older to be CSA.

About a third of the studies (32%) also included in their definition peer experiences that were unwanted or forced.

Fourteen percent of the studies defined sexual experiences with relatives as CSA, although this criterion generally included an age discrepancy.

Prevalence rates.

For male participants, 26 samples provided data usable for estimating the prevalence rate of CSA.

Of the 13,704 male participants in these samples, 14% reported sexual experiences classifiable as CSA under the various definitions. The unweighted mean prevalence was 17% ( SD = 10%), with a range from 3% to 37%.

For female participants, 45 samples provided data that were usable for estimating the prevalence rate. Of the 21,999 women in these samples, 27% reported sexual experiences classifiable as CSA. The unweighted mean prevalence was 28% ( SD = 16%), with a range from 8% to 71% (see the Appendix for listing of sample-level prevalence rates).

Types of CSA.

Twenty one (35.6%) of the 59 studies contained a breakdown of the types of CSA that occurred along with their frequencies.

Types listed varied from study to study, including acts such as

an invitation to do something sexual,

exhibitionism,

fondling,

masturbation,

oral sex,

attempted intercourse, and

completed intercourse.

Many authors referred to this increasing level of sexual intimacy as "severity" or "seriousness."

Using the reported prevalence rates of the various types of CSA from these studies, we estimated the distribution of four basic types of CSA in the college population:

exhibitionism,

fondling,

oral sex, and

intercourse.

For exhibitionism, we included reports of being shown or showing sex organs in a sexual context. Researchers assessed exhibitionism by asking participants if someone had shown, exhibited, or exposed to them his or her sex organs, or if they had shown, exhibited, or

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exposed their sex organs to the other person at the other person's request.

For fondling, we included reports of sexual touching and masturbation. Researchers assessed fondling usually by asking participants if they had experienced fondling or genital touching; occasionally they included nongenital touching as examples of fondling.

For intercourse we included both attempted and completed instances.

Estimates were based on weighting prevalence rates by sample size across samples. Some studies reported prevalence rates for two combined types (e.g., exhibitionism and fondling) rather than reporting their rates separately. In these cases, we divided the rates evenly between the two types. Because a number of studies categorized SA participants exclusively into the most "severe" type of CSA experienced, the prevalence of less severe types is likely to be underestimated.

The top half of Table 1 shows the estimated prevalence rates in the college population for the different types of CSA for SA women and men separately and combined.

To provide a frame of reference for these results, we estimated corresponding prevalence rates for SA persons in the general population based on reports from 3 national samples

( Baker & Duncan, 1985 ; Laumann et al., 1994 ; López, Carpintero, Hernández, & Fuertes, 1995 ).

Data in these studies were obtained in face-to-face interviews of respondents selected to be representative of their nations (Britain, United States, and Spain, respectively).

The strength of face-to-face interviews in obtaining valid data along with the high response rates of these studies (unweighted mean = 83%) suggest that their prevalence rates serve as good population estimates.

As with studies based on college samples, these studies used varying definitions of CSA (e.g., contact only vs. both noncontact and contact sex) and of types of CSA such as intercourse (i.e., completed only vs. both attempted and completed).

The bottom half of Table 1 displays the estimated prevalence rates for the different types of CSA for SA persons in the general population. Comparing the college and national distributions indicates similar prevalence rates for intercourse for women; SA college men, however, show a higher rate (33%) than SA men in the general population (13%).

Because intercourse is frequently viewed as the most severe or serious type of CSA, these results imply that SA college students, especially men, do not experience less severe CSA than SA persons in the general population.

Table 1
Prevalence Rate Estimates of Four Types of CSA in College and National Populations

Sample/Gender	k	N	Exhibitionism	Fondling	Oral Sex	Intercourse (a)
College
female	13	2172	32%	39%	3%	13%
male	9	506	22%	51%	14%	33%
combined (b)	26	2918	28%	42%	6%	17%
National (c)
female	3	590	38%	67%	9%	16%
male	3	366	25%	69%	22%	13%
combined	6	956	33%	68%	14%	15%

Note. k is the number of samples and N is the number of SA respondents in these samples that prevalence rate estimates of types of CSA are based on. Prevalence rate estimates are weighted means of prevalences from individual samples. College estimates come from studies included in the current review; national estimates come from 3 studies of national samples (Baker & Duncan, 1985; Laumann et al., 1994; Lopéz et al., 1995)

(a) In some college and national studies, intercourse included both attempted and completed acts
(b) Combined values were based on two additional studies (with a male and female sample in each) that reported only combined results
(c) For exhibitionism, only data from Lopéz et al. were reported (female: k=1, N=203; male k=1, N=134; combined k=2, N=337);
for oral sex, only data from Laumann et al. and Lopéz et al. were reported (female: k=2, N=476; male: k=2, N=291; combined k=4, N=767).

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Severity or seriousness of CSA is often not only viewed as a function of the level of intimacy of the sexual act but also as a function of the closeness of the relationship between the SA person and his or her partner or abuser (e.g., Edwards & Alexander, 1992 ; Laumann et al., 1994 ).

On the basis of the studies providing relationship information, we estimated

the proportion of the college population that has experienced close family CSA (biological or stepparents, grandparents, older siblings) and

the proportion that has experienced wider family CSA (including both close family CSA and CSA with other relatives).

Estimates were performed for SA women and men separately and combined (see Table 2 ).

Results indicate that only a small proportion of SA college students experience close family CSA (16% for women and men combined), with women experiencing it two and a half times as much (20%) as men (8%).

Table 2
Prevalence Rate Estimates of Relationship Between CSA Respondents
and Partners/Abusers in College and National Populations

	Wider Family CSA				Close Family CSA
	College (a)		National (b)		College (c)		National (b)
Gender	N	%	N	%	N	%	N	%
female	2735	37	606	34	792	20	606	15
male	580	23	375	13	270	8	375	4
combined	3569	35	981	26	1275	16	981	11

Note. Close family CSA includes sexual relations with very close relatives (e.g., biological or step parents, grandparents, older siblings). Wider family CSA includes both close family CSA and relations with other relatives.
Prevalence rate estimates are weighted means of prevalences from individual samples.
College estimates come from studies included in the current revies; national estimates come from 3 studies of national samples (Baker & Duncan, 1985; Laumann et al., 1994; Lopéz et al., 1995)

a Based on 21, 9, and 33 samples for females, males, and combined, respectively
b Based on 3, 3, and 6 samples for females, males, and combined, respectively
c Based on 10, 6, and 19 samples for females, males, and combiend, respectively.

To provide a frame of reference, we estimated prevalence rates for SA persons in the general population based on reports from the three national samples used previously to estimate prevalence rates for different types of CSA.

As is shown in Table 2 , estimated prevalence rates for close and wider family CSA are similar in the college and general populations.

It is important to note that estimates from the college samples do not underestimate the occurrence of close or wider family CSA relative to estimates based on national samples.

This result further implies that SA college students as a group do not experience less severe CSA than SA persons in the general population.

Another commonly used indicator of severity of CSA is its frequency of occurrence (i.e., multiple occurrences are viewed as more severe than a single episode). We estimated the proportion of college students with a history of CSA who experienced more than one CSA episode using all 11 studies that provided this information. We then compared these results with national population estimates based on the same three studies of national samples used above.

In the college samples, based on 11 studies with 1,195 SA participants, the weighted mean percentage that had more than one CSA experience was 46%; for the three national studies, based on 990 SA respondents, the weighted mean percentage was 52%.

The unweighted mean percentages were identical in the two groups: 49% ( SD = 11%) for the college samples and 49% ( SD = 15%) for the national samples.

These results further indicate similarity in CSA severity in the college and general populations.

Finally, force or threat of force is commonly used as an indicator of CSA severity. We estimated the proportion of SA college students whose CSA involved force or threat of force based on the 10 studies (with six male and six female samples) that provided this information.

For 355 SA men in these samples, the weighted mean percentage that experienced some degree of force or threat was 23%.

For 753 SA women, the weighted mean percentage experiencing some degree of force or threat was nearly twice as much (41%).

Unweighted mean percentages across samples were 22% ( SD = 21%) for men and 42% ( SD = 26%) for women.

The rather large standard deviations for the unweighted estimates suggest that these estimates should be viewed cautiously.

An additional study reported that 31% of their SA students, males and females combined, experienced some degree of force or threat of force - a percentage intermediate to, and thus consistent with, the male and female estimates just presented. National population estimates were not possible in the case of force or threat of force, because none of the three studies used above provided relevant data.