• Alfred Kinsey's 1948 and 1953 Studies
• Selected Research Findings from Kinsey's Studies
• For More Information

See also Alfred Kinsey's Heterosexuality Homosexuality Rating Scale and Data from other sex research studies.

Alfred Kinsey's 1948 and 1953 Studies

• Kinsey, Alfred C. et al. (1948/1998). Sexual Behavior in the Human Male. Philadelphia: W.B. Saunders; Bloomington, IN: Indiana U. Press. Currently out of print.
• Kinsey, Alfred C. et al. (1953/1998). Sexual Behavior in the Human Female. Philadelphia: W.B. Saunders; Bloomington, IN: Indiana U. Press. [Please note that Female volume is a source of many comparisons of findings between male and female behavior.]
• Gebhard, Paul H. and Johnson, Alan B. (1979/1998). The Kinsey Data: Marginal Tabulations of 1938-1963 Interviews Conducted by the Institute for Sex Research. Philadelphia: W.B. Saunders; Bloomington, IN: Indiana U. Press. [Augments data in the original 1948 and 1953 studies and discusses Kinsey's interview and sample.]

Scope:

To describe individual and group variations in human sexual behavior using taxonomic methods (primarily concerned with the measurement of variation in series of individuals that stand as representatives of the species being studied) from biology. Kinsey sought to accummulate "an objectively determined body of fact about sex" (p. 5 Male) that readers of the reports could use to make interpretations that fit with their understanding of "moral values and social significances" (p. 5, Male). He looked at quantifiable male sexual "outlets" to orgasm: masturbation, nocturnal emissions, heterosexual petting, heterosexual intercourse, homosexual relations, and intercourse with animals of other species; and at what factors might account for variations in sexual behavior, including marital status, age, educational level, occupational class, rural-urban background, religious group, geographic origin, and age at adolescence. He then compiled data for the female. Data was gathered from 1938 to 1963, when the project was closed.

Sample:

5300 white males and 5940 white females provided almost all the data, with the majority of participants being younger white adults with some college education. (This part of the sample is referred to as the "College Sample.") Kinsey tried to compensate for volunteer bias in his sample by interviewing 100% of the individuals available in a given organization or group. Approximately 25% of the sex histories came from these 100% groups. (Kinsey did not believe a random sample was possible.)

Method:

Kinsey used in-depth, face-to-face interviews by highly trained interviewers. In each history a subject would be questioned on up to 521 items, depending on his/her specific experience (the average in each case being near 300). Histories covered social and economic data, physical and physiologic data, marital histories, sexual outlets, heterosexual histories, and homosexual histories.

Research Findings from Kinsey's Studies

Included here are data on selected topics from Alfred Kinsey's Male and Female volumes (as well as from Gebhard and Johnson's Kinsey Data) about which the Institute frequently receives questions:

Anal Sex

11% of males reported, in marriage, a frequency of anal sex ranging from a single attempt to often, (Table 334, p. 383, Kinsey Data, College Sample, as corrected by data analysis of computer tape, 4/93).

There is little data in the original Kinsey Studies regarding heterosexual or homosexual anal sex. Kinsey found some anal play in some of the male marital histories and occasional instances of anal coitus but not enough to determine "the incidence of individuals who are specifically responsive to such stimulation," (p. 579, Male). He reported, among the male homosexual, occasional individuals brought to orgasm anally, (p. 579, Male). For females, Kinsey said that good incidence data was not available, (p. 585, Female).

Males:

Kinsey estimated that nearly 46% of the male population had engaged in both heterosexual and homosexual activities, or "reacted to" persons of both sexes, in the course of their adult lives (p. 656, Male). 11.6% of white males (ages 20-35) were given a rating of 3 (about equal heterosexual and homosexual experience/response) on the 7-point Kinsey Heterosexual-Homosexual Rating Scale for this period of their lives (Table 147, p. 651, Male).

Females:

Kinsey found only a very small portion of females with exclusively homosexual histories. He reported that between 6 and 14% of females (ages 20-35) had more than incidental homosexual experience in their histories. (p. 488, Female). 7% of single females (ages 20-35) and 4% of previously married females (ages 20-35) were given a rating of 3 (about equal heterosexual and homosexual experience/response) on the 7-point Kinsey Heterosexual-Homosexual Rating Scale for this period of their lives.(Table 142, p. 499, Female).

Age at first intercourse:

Males:

20.9% by age 16

10.7% at age 17

11.5% at age 18

10.8% at age 19

Females:

6% by age 16

4.9% at age 17

9.1% at age 18

11.2% at age 19

(Table 218, p. 267, Kinsey Data, College Sample). For further male/female comparisons on premarital sex, see p. 330-32, Female.

Frequency of Marital Coitus

Females (average frequency reported):

2.8 times a week, in late teens

2.2 times a week, by age 30

1.0 times a week, by age 50

Male data were comparable.

(p. 348-9, 351, Female). For further male/female comparisons of Martial Coitus, see p. 392, Female.

Length of Coitus:

Males:

17.6% of males reported ejaculation less than 2 minutes after intromission

47.6% less than five minutes in coitus in first marriage

22.9% claimed to have lasted 10 or more minutes, (Table 324, p. 373 Kinsey Data, College Sample).

Females:

22.8% of females reported reaching climax less than 2 minutes after intromission

52.6% less than five minutes in coitus in first marriage

19% claimed to have lasted 10 or more minutes, (Table 324, p. 373 Kinsey Data, College Sample)

In the discussion of marital coitus in the Male volume, Kinsey speculated that for perhaps three-fourths of all males, orgasm was reached within 2 minutes after initiation of coitus, and reported this as a frequent source of marital conflict (p. 580, Male).

Positions, Coital

Kinsey found the most frequently reported coital position to be male-above, and the most common variant position to be female-above.

Females:

100% used male-above position in marital coitus

45% used female above

31% used side-by-side positions

15% rear vaginal entry

9% sitting; and 4% standing (p.400, Female)

Males:

In the Male volume, Kinsey estimated that as much as 70% of the population only used the male-above position in coitus, (p. 578, Male).

In about 35% of the male College Sample histories the female-above-male position was used (Table 95, p. 372, Male).

Preference for Coitus in Light or in the Dark:

40% of the males in the sample preferred to have sexual activities in some light

19% of the females preferred to have sexual activities in some light, (p. 664-5, Female)

Erogenous Zones

The Kinsey interviews showed that there is no part of the human body which is not sufficiently sensitive to effect erotic arousal for at least some individuals in the population. He estimated that breasts and especially the nipples of the breasts were erotically sensitive in perhaps half of the females (with breast stimulation alone sufficient for orgasm in a very small percentage of females), (p. 157, 161, Female). There were some 2 % of females who even by their late 40s had never recognized any sexual arousal under any sort of condition. (p. 512, Female

Incidence

Males: Kinsey estimated that approximately 50% of all married males had some extramarital experience at some time during their married lives (p. 585, 587, Male).

Females: Among the sample, 26% of females had had extramarital sex by their forties. Between 1 in 6 and 1 in 10 females from age 26 to 50 were engaged in extramarital sex, (p. 416, Female).

Number of Extramarital Partners

Males:

Number of extramarital sexual partners, not counting prostitutes, during first marriage:

71.6% reported none

16.7% reported 1-3 partners

5.6% reported 4-6 partners

5.9% reported 7 or more (Table 351, p. 400, Kinsey Data, College Sample)

Females:

Number of extramarital sexual partners, not counting prostitutes, during first marriage:

79% reported none

15.7% reported 1-3 partners

2.4% reported 4-6 partners

2.7% reported 7 or more (Table 351, p. 400, Kinsey Data, College Sample)

Males:

• 84% of the males in the sample indicated that they were sometimes aroused by thinking of sexual activities with females (p. 665, Female).
• 89% of males reported having used sexual fantasy with masturbation (p. 225, Kinsey Data, College Sample).

• Only 3-4 males, out of more than 5000 in the sample, had experienced ejaculation by fantasy alone (p. 517-8, Male).

Females:

• 31% insisted they had never been aroused by thinking about males or sexual relations with them.
• 69% of females reported erotic fantasies about males, (p. 665, FEMALE).
• 64% of the female sample used fantasy as part of masturbation, (p. 164, Female).
• Some 2% of females in the sample had reached orgasm by fantasizing erotic situations (without any tactile stimulation), (p. 163, FEMALE).

Duration of foreplay in marriages, (from sexual histories):

11% of marriage histories, foreplay lasted 3 min.

36% of marraige histories, foreplay lasted 4-10 min.

31% of marriage histories, foreplay lasted 11-20 min.

22% of marraige histories, foreplay lasted more than 30 min, (p. 364, Female)

Comparative data:

18.5% of males and 20.7% of females reported foreplay of 3-7 minutes in marital coitus

19.5% of males and 21.2% of females reported foreplay of 8-12 minutes

19.1% of males and 13.8% of females reproted foreplay of 13-17 minutes (Table 315 p. 364, Kinsey Data, College Sample)

In descending order of techniques of foreplay in marital coitus, Kinsey found:

simple lip kissing (99.4%);

manual stimulation of female breast (98%);

manual stimulation of female genitalia (95%);

oral stimulation of female breast (93%);

manual stimulation of the male genitalia (91%);

deep kissing (87%);

oral stimulation of the female genitalia (54%);

oral stimulation of the male genitalia (49%), (p. 361, FEMALE).

See also Tables 316-323, p. 365-372, Kinsey Data for techniques of foreplay.

Kinsey said in both the Male and Female volumes that it was impossible to determine the number of persons who are "homosexual" or "heterosexual". It was only possible to determine behavior at any given time. (See Kinsey's Heterosexual-Homosexual Rating Scale.)

Instances of at least one same-sex experience to orgasm:

• 37% of males
• 13% of females, (p. 650, Male, p. 475, Female)

Males:

• 10% of males in the sample were predominantly homosexual between the ages of 16 and 55
• 8% of males were exlusively homosexual for at least three years between the ages of 16 and 55. (p. 651, Male)
• 4% of white males had been exclusively homosexual after the onset of adolescence up to the time of their interviews, (p. 651, Male).

Females:

• 2 to 6% of females, aged 20-35, were more or less exclusively homosexual in experience/response, (p. 488, Female)
• 1 to 3% of unmarried females aged 20-35 were exclusively homosexual in experience/response, (Table 142, p. 499, and p. 474, Female).

Males:

92% of males reported that they had masturbated (p. 499, Male).

Females:

62% of females reported that they had masturbated (p. 142, Female).

45% of females who reported having masturbated indicated that they could reach orgasm within 3 minutes (p. 163, Female).

Masturbation techniques reported by females:

84% used clitoral and labial manipulation

20% used vaginal insertion

11% used breast stimulation

10% used thigh pressure

5% muscular tension

2% had fantasy alone to reach orgasm; and

11% used other techniques (p. 189, Female)

Masturbation was the most important sexual outlet for single females and the second most important sexual outlet for married females, providing: 7-10% of orgasms for those 16-40 (p. 525, 532, Female). In males, masturbation after marriage occurred with reduced frequency (p. 507, Male).

For further female/male comparisons of masturbation, see p. 173, Female.

Kinsey found that attitudes toward nudity differed by level of education and socioeconomic status. Still, about half (41%) of males in the College Sample reported sleeping nude, and half of the married females in the sample had regularly slept nude, (p. 366 Male and p. 365, Female).

Percentage of males who said they had performed cunnilingus:

before marriage about 10%

in marriage 48.9% (Tables 207, p. 256 and Table 322, p. 371, Kinsey Data, College Sample)

Percentage of females who said they had performed fellatio:

before marriage, 19.1%

in marriage 45.5% (Table 208, p. 257 and 323, p. 372, Kinsey Data, College Sample)

Percentage of males who reported experiencing homosexual fellatio, with climax, at least once:

14% had performed fellatio

30% had received fellatio (p. 373, Male)

Sources of first ejaculation for males:

68.2% masturbation

13.11% nocturnal emission

12.53% coitus

4.33% homosexual contact

other sources, including premarital petting (p. 190, Male)

Sources of first orgasm for females:

40% masturbation

27% coitus

24% premarital petting (not found in chart)

5% nocturnal dreams

3% homosexual

1% other sources (p. 545, Female)

10% of all females in the sample had never reached orgasm in their marital coitus, (footnote, Table 113, p. 408, Female). 39-47% of females reported reaching orgasm in nearly all of their marital coitus, (Table 112, p. 408, Female). About 50% of females had experienced orgasm by age 20; about 90% by age 35. (p. 513, Female)

Multiple Orgasm:

Females: 14% of females in the sample reported regularly responding with multiple orgasms, (p. 375, Female).

Males: 15-20% of males in their teens and twenties reported that they were capable of repeated orgasm in a limited period of time. Kinsey stated that most men lost this capacity by age 30 or 40, (p. 233, Male).

For comparisons of orgasm in marital coitus, see p. 392-393, Female.

Nocturnal Sex Dreams and Orgasms:

Approximately two-thirds of females reported overtly sexual dreams (and Kinsey estimated over the life course that 70% of females experienced sex dreams), and almost 100% of the males (p. 196, 215, Female).

By age 45, 37% of females in the sample had experienced a sex dream with orgasm (p. 196, Female); Kinsey reported that 83% of males reported nocturnal emissions, with or without dreams (p. 518-199, Male).

The frequencies with which the average female had nocturnal orgasms stayed fairly constant for single and married females of all ages (adolescence to 50 yrs. old), (p. 200, Female). The highest incidence (70%) and frequency for males came in the late teens, but declined in the thirties, (p. 523, Male).

In the male, the average maximum sexual frequencies for the total sexual outlets occur between 16 and 20, (Table 45, on p. 226, and Table 60, on p. 266, Male).

In the female, solitary sexual activities (such as masturbation, nocturnal dreams to orgasm) gradually rise to their maximum point. They level off and then decline after 55 or 60 years of age. (p. 353, Female). Kinsey thought that female instance of coitus was dependent on the male's sexual behavior. (p. 353-4, Female).

Occurs in:

Males:

67-98%, depending on socioeconomic level.

68% by age 18 had experienced premarital coitus, (p. 549-52, and Table 136, p. 550, Male).

Females:

about 50%, (p. 286, and Table 75, p. 333 and Table 79, p. 337, Female).

• 69% of white males have had at least one experience with a prostitute;
• among unmarried males, sex with a prostitute was about 10% of the total premarital intercourse;
• among married males, sex with a prostitute was never more than 1.7% of the total sexual outlet reported, (p. 597, 599, 601, and Table 97, p. 382, Male).

Kinsey's studies do not say much about sadomasochistic behaviors. Some 12% of females and 22% of males reported having an erotic response to a sadomasochistic story, and 55% of females and 50% of males reported having responded erotically to being bitten, (p. 677-8, Female).

The above data have been provided for quick reference. We have tried to present this data in a clear and concise way; something made difficult by the complexity of Kinsey's monographs. If you have questions about the above data, or need further information, contact Information Services.

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