By Christian Jarrett

Especially if you are in a long-term relationship your own sexual functioning is not a purely an individual matter but is bound up with your partner’s. Previous research has looked at this dynamic, finding for example that people are generally happier with their sex lives when they have the perception that they and their partner are sexually compatible. Surprisingly, however, before now the influence of your partner’s broader personality traits on your own sex life had not been studied.

A German study of nearly a thousand long-term couples (98 per cent of them heterosexual) is the first to look at this question. Among the stand-out findings is that, for women, having a more conscientious partner was associated with having better sexual functioning and a more satisfactory sex life.

Writing in The Journal of Sex Research, the researchers, led by Julia Velten at Ruhr-Universität Bochum, suggested that “men who are thorough and dutiful may feel the need to satisfy their partner sexually, which may in turn lead to better sexual function of their partners.”

The researchers interviewed each participant and his or her partner individually over the phone about their personality traits; their sexual responsiveness (that is, how easily aroused or easily turned off they are, which psychologists consider stable traits and refer to as “sexual excitation” and “sexual inhibition”); and finally, in detail, about their sexual function. For women this last measure incorporated sexual satisfaction, arousal, desire, lubrication, pain, and orgasm frequency; for men it was focused on erectile function but also included questions about desire, satisfaction and orgasm.

The participants had an average age of 51 and had been in their current relationships for an average of 24 years.

Consistent with past research, the female and male participants’ own traits were relevant to their sexual function. For both sexes, and to no great surprise, being more easily sexily aroused and less easily turned off (for example by stress at work or performance anxieties) were associated with healthier sexual function.

In terms of their own personality traits, only the participants’ own higher levels of conscientiousness (a trait that incorporates self-discipline, orderliness and ambition) were correlated with healthier sexual function – perhaps because people high in this trait put more effort into their sex lives.

Surprisingly, given past research suggesting that extraverts have more active and enjoyable sex lives (and the same for people higher in openness-to-experience), the participants’ own scores on these traits were not related to their sexual function, perhaps because they overlapped so much with the measures of sexual excitation and inhibition that were included in the statistical analysis.

More novel and interesting are the effects on participants of their partners’ traits. Men who were easily aroused benefited sexually if their partner was disposed the same way. “In men who are easily aroused by erotic fantasies or visual stimuli, having a partner who responds in a similar way may facilitate sexual function,” the researchers said.

Meanwhile, for women, having a partner prone to greater sexual inhibition was associated with their own sexual function being poorer. “Especially in couples who limit their sexual interactions to penile-vaginal intercourse, women whose partners are more sexually inhibited … may experience fewer sexual interactions that provide enough stimulation,” the researchers said.

In terms of partners’ personality traits – the key trait for women, as mentioned above, was their partner’s conscientiousness – women with more conscientious partners tended to report their own sexual function to be healthier. “Conscientious individuals might have the tendency ‘not to let it slip’ and to continue working on the sexual relationships with their partners,” the researchers said.

Also relevant for women was their partner’s agreeability – those with less agreeable partners reported healthier sexual function. Meanwhile, men reported healthier sexual function when their partners scored higher in emotional instability. We await explanations for these particular associations.

Outside of individual traits, men’s age was, unsurprisingly, negatively correlated with their sexual function scores. However, across the couples, relationship duration was not correlated with participants’ sexual function. “This finding implies that a healthy sexual life is possible even in long relationships,” the researchers said.

Among the study’s limitations is that shy couples or couples with greater relationship problems are less likely to have agreed to take part. Also, the results only present a static picture of the dynamics between the measured variables – we don’t know how they are causally related to each other. Nonetheless, this study breaks new ground by uncovering the ways that our partner’s personality might have an influence on our own sexual function.

“Improving our knowledge about intra- and inter-personal factors contributing to sexual concerns is valuable to further develop psychological treatments for individuals and couples who are distressed by low sexual function,” the researchers said.

—Exploring the Impact of Personal and Partner Traits on Sexuality: Sexual Excitation, Sexual Inhibition, and Big Five Predict Sexual Function in Couples

Christian Jarrett (@Psych_Writer) is Editor of BPS Research Digest