Masturbation and partnered sex: Substitutes or complements?

That is the title of a new paper by Mark Regnerus (University of Texas at Austin), Joseph Price and David Gordon (both Brigham Young University), and published in the journal Archives of Sexual Behavior (I don't see an ungated version online). The title pretty much explains what the authors are trying to establish, using data on 15,738 adults (aged 18-60 years) from the Relationships in America study in 2014.

Essentially they are testing two competing models. The first is the compensatory model, which:

...holds that masturbation and paired sexual activity are inversely associated; that is, masturbation is an outlet for sexual energy when paired sexual activity is not possible, either due to lack of a partner or the unwillingness or inability of a partner to engage in sex as often as desired.

The compensatory model suggests that masturbation and partnered sex are substitutes. In contrast, the complementary model suggests that they are complements, i.e.

...that paired sex stimulated demand for additional sex and sexual activities, including masturbation.

Past studies have shown that men's behaviour is consistent with the compensatory model, while women's behaviour is consistent with the complementary model. However, Regnerus show that it isn't quite that simple, and that sexual contentment matters. Their results showed that:

Among men who were content with their sexual frequency, we saw few discernable trends in the likelihood of masturbation based on recent sexual frequency... However, the pattern was different for men who were sexually discontented. Among them, the odds of recent masturbation among those who have had sex 2-3 times, or 4 or more times, in the past 2 weeks were significantly lower than those who have not had sex at all in the past 2 weeks.

For women, the pattern appeared to be reversed. The odds of recent masturbation among women who reported being content with their sexual frequency were more than twice as high if they had had sex four or more times when compared to those who not had [sic] any sex in the past 2 weeks... In this way, sex and masturbation again appeared complementary among them. Meanwhile, there was no discernable association, net of controls, between frequency of recent sex and masturbation for women who reported sexual discontentment.

The concluded that:

...the compensatory model modestly fits sexually unsatisfied men, and a complementary model fits sexually satisfied women.

The main downside of this study of course is that it was based on a cross-sectional sample, so the results are correlations, not causal. They had a number of control variables, including most of the obvious ones like whether people were partnered. However, they only ever look at the differences between people, and it's possible that there is something systematically different between those who report masturbating and those who don't which isn't captured by the variables in the model. Having longitudinal (panel) data would go some way (but not all the way!) towards solving this issue, since it would allow you to observe at least some of the people in the sample at times when they are content, and at other times when they are not, and see if that affects the likelihood of reporting masturbation. Still, for the moment this is the best study on the topic and provides a more nuanced picture than earlier studies.

[HT: Marginal Revolution]