Saturday, May 29, 2010

Sexual orientation, body size, and shape

Using MIDUS data, I lumped together homosexuals and bisexuals, giving me 53 gay men and 45 lesbians. I then calculated waist-to-hip ratios for everyone:

Mean waist-to-hip ratio

Straight men .97
Gay men .95
Straight women .85
Lesbians .88

Compared to gay guys, straight men have more tubular (masculine) bodies, while among women, lesbians have the more straight-up-and-down shape. The differences are statistically significant. The guy gap is only two-tenths of a standard deviation (SD), but the female gap is four-tenths of an SD--a moderate difference. 

Next, I calculated the mean Body Mass Index (BMI) for each group:

Mean Body Mass Index

Straight men 28.35
Gay men 27.21
Straight women 27.53
Lesbians 28.27

Straight men and lesbians have similar numbers and are heavier than their gender counterparts. Gay men and straight women also have similar BMIs (gay men are actually thinner). The differences, however, are not statistically significant.

Finally, let's look at height:

Mean height (inches)

Straight men 70.2
Gay men 69.6
Straight women 64.3 
Lesbians 64.8

For the men, straight guys are 6/10 of an inch taller. Lesbians are half of an inch taller than hetero females, but neither of the differences are significant.

Overall, the numbers suggest that gay men are more feminine than straight men, while lesbians are more masculine than heterosexual women.  


  1. Although the sample sizes are small, this is about what I would have expected. WHR is affected by one's body shape and where one stores accumulated fat, but it is also affected by how much fat is actually being stored. Since gay men are trying to attract other men, they have an incentive to stay in shape, whereas women care somewhat less about such matters so lesbians have less incentive than their counterparts. I'm pretty sure most or all of the difference is explained by behavior and not by body type.

  2. It's also worth pointing out that one could argue gay men are more masculine then straight men as well as more feminine since they are closer to the ideal for female attraction in two of the the three categories (WHR of .9 and BMI of 20-24). It depends on whether you see masculinity on an absolute scale as "distance from feminine" or as an ideal from the feminine perspective.

  3. Mean BMI 27!!!! the MEAN!!!

    How terrifying is that!!!!!

  4. Anonymous10:18 PM

    It would be interesting to know if birth weight for boys who wound up being gay differs from those who wound up being straight.

  5. Anonymous2:18 AM

    Gay men probably have a lower WRH than straight men because they are less heavy, not independantly. Likewise the contrary for lesbians and straight women. There's no hormonal difference in how homosexual and heterosexual people deposit fat.

  6. Anonymous6:47 AM

    I don't know where you get the idea that a high waist/hip ratio is "masculine." A high ratio simply indicates lots of fat being stored around the waist. A better indication of masculine form would be the V taper, i.e. chest to waist ratio.


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