Meston and Buss (1)Meston, C.M. and Buss, D.M. Why humans have sex. Arch Sex Behav. 2007; 36: 477–507 identitified 237 reasons people have sex in 2007 and collapsed them into the 140 item YSEX? inventory. The current study by Wyverkens, et. al., used YSEX! with a broader audience (N=4,655, age range of 13-83, 55/45% female to male ratio) looking for variations in motivation for sex.

As with Meston and Buss, this survey showed that while there are differences in sexual motivation for men and women, we are quite similar in the top resons for having sex. The top two reasons for having sex were the same in all age groups and gender (though order switched for females under 18):

  1. It’s fun
  2. It feels good

The third reason was “I wanted to experience the physical pleasure” or (for teen women and young adult males) “I was horny”. 

Sex Differences

Significant differences in motivation were found for some ages between males and females, but Cohen d (2)Cohen d was used to test how great the effect gender of respondent was on choice showed moderate to low effect sizes.

Some of the largest differences (significant and higher effect sizes) were between adult men and women (22-55 years old). Men reported more physical reasons for pursuing sex (especially physical desireablity of partner and decrease of stress) and women reported more emotional reasons (especially love and commitment) and more insecurity reasons (especially self-esteem boost). Women were also more likely to have sex for duty or pressure,  and men for pleasure though effect sizes were small.

Age Differences

Because this is not a longitudinal study, age based differences cannot be intepreted as the effect of growing older. They may also be cohort effect. Millenials seem to approach sex differently than Baby Boomers and this may be the explaination for the age difference.

Age differences were seen in several factors and sub-factors. Young adult women (18-22), for example, sought sex as a stress relief significantly more than older women (≥55). Older men and women scored pleasure lower than younger men and women. Physical desireability also drops off as a motivating factor for older men and women.

For emotional subfactors, men showed a significantly higher love and commitment motivation in the 18-22 yange than those younger than 18 or 22-55. Women’s scores on the subfactor expression were significantly higher in those 18 to 22 years old than in those 22 to 55 years old.


Why do people have sex and does the reason vary by gender or age? This is the question addressed by the current study. While overall a good study with some fascinating findings, there are a couple areas to attend to.


The sample consists of 4,655 respondents who were recruited to take an online, anonymous survey through “different channels (such as leaflets, advertisements, posts on social media, calls in youth clubs, retirement homes, etc), thereby combining a snowball sampling technique and a purposeful sampling technique”. While “nationality” was collected, results were not reported. Ethnicity was not queried. Over 3/4 of the adult group had at least a college education (8.7% post graduate). Average length of relationship for adults was 8.5 years and 15.76 for older adults.


Mean sexual satisfaction was above 7 (1-10 scale) for adults. It was slightly higher for younger and significantly lower for older adults (6.24). No significance in gender differences.

Interestingly, while satisfaction dropped as participants age increased, the importance of sex increased with age cohort. Researchers pointed this out as a part of the demographics, but didn’t discuss it.

Primary problem –

  • Did not address ethnic differences or any sample stats on diversity of sample.
  • 22-55 is a HUGE range for an age grouping.


The YSEX! questionnaire is the core of this research. It was developed using a two part strategy. Part 1 was collecting an open list of 715 reasons people have sex from a convenience sample (“Please list all the reasons you can think of why you, or someone you have known, has engaged in sexual intercourse in the past.”). No demographics are provided for this sample so no assessment can be made of the completeness of this list for different ages, ethnicities, social status, religion, etc. The initial 715 reasons were collapsed to 237 by editors. This list of 237 became the basis for Part 2. This second strategy was conducted with a sample of undergraduate students (N=1549) of which only 4% were African American (15% Hispanic, and 15% Asian American). Further, 32% of the males and 27% of the females were virgins at the time of the study and only 4% were married. Faith demographics were reported, but no mention was made on impact of faith to the results.

The authors of the YSEX! questionnaire acknowledge the lack of diversity and suggest the 13 factors discovered may not transfer across age or culture. This does not invalidate the current study, but weakens it, especially since some internal consistency values were poor for factors in this study.

Internal consistency for this study showed some differences from the first. No one endorsed “I wanted to give someone else a sexually transmitted disease” in this study and reproductive reasons (i.e., “I wanted to have a child”) seemed to reflect a separate factor. These were not considered significant enough to create a problem for this study.


So What? …

“Most people are driven by the pleasure of sex.” The biggest take away the authors report is that the primary reason for seeking sex for both males and females is still pleasure. I think it is worth noting that while about the pleasure, neither of the top two, “It’s fun”, nor “it feels good”, are exclusively physical. “I was horney” and “I wanted to experience the physical pleasure” seem clearly physical, so physical pleasure is definitely in the top three for all age groups. Researchers see this as contrary to assumptions by Rosemary Basson (3)Basson, R. (2000). The female sexual response: A different model. Journal of Sex &Marital Therapy, 26(1), 51-65..

Seeking closeness hit the top five for two groups: women over 55 (#4) and men 22-55 (#5). This is a bit different from some studies they mention and from the Hart, Weber, and Taylor (4)Hart, A. D., Weber, C. H., & Taylor, D. (1998). Secrets of Eve: understand the mystery of female sexuality. Nashville, TN: Word. study ISW often references where closeness is a top reason for women.

Physical vs emotional. “For sex, we found that within almost each age category (except for adolescents), men were more likely to have sex for physical reasons, whereas women were more likely to be motivated by emotional and insecurity reasons.” Despite above statements, this seems to be more supportive of Basson than they seem to suggest.

Age decreases physical motivation and satisfaction with sex.


Wyverkens, E., Dewitte, M., Deschepper, E., Corneillie, J., Van der Bracht, L., Van Regenmortel, D., . . . T’Sjoen, G. YSEX? A Replication Study in Different Age Groups. The Journal of Sexual Medicine. doi:10.1016/j.jsxm.2018.02.012

References   [ + ]

1. Meston, C.M. and Buss, D.M. Why humans have sex. Arch Sex Behav. 2007; 36: 477–507
2. Cohen d was used to test how great the effect gender of respondent was on choice
3. Basson, R. (2000). The female sexual response: A different model. Journal of Sex &Marital Therapy, 26(1), 51-65.
4. Hart, A. D., Weber, C. H., & Taylor, D. (1998). Secrets of Eve: understand the mystery of female sexuality. Nashville, TN: Word.