Sexual desire for a long-term romantic partner may be linked to increased desire for alternative partners, according to a study published in Human Nature.
Traditional relationship science posits that sexual desire enhances relationship maintenance, reducing interest in alternative partners. However, evolutionary perspectives suggest sexual desire might not be partner-specific. Instead, desire for one partner may increase overall sexual motivation, leading to heightened interest in both the romantic partner and potential alternatives.
Traditional theories suggest sexual desire for a long-term partner helps maintain romantic bonds and diminishes interest in alternatives, enhancing relationship stability. In contrast, evolutionary perspectives argue that sexual desire evolved to seek out reproductive partners, making it non-exclusive. Sierra D. Peters and colleagues examined how sexual desire operates in long-term relationships.
The researchers employed two different methodological approaches: a daily-diary study and an experimental study, both designed to explore the relationship between sexual desire for a romantic partner and interest in alternative partners. In the first study, 196 individuals from 98 newlywed couples (predominantly heterosexual) participated in a longitudinal daily-diary survey. The couples, who had been married for less than four months, were recruited through Facebook advertisements and community flyers.
Each participant completed daily surveys for 14 days, assessing their sexual desire for their partner and their interest in alternative partners. This process was repeated annually for two years, creating three waves of data collection. Participants reported their level of desire for their partner using a single-item measure, rating their daily desire on a 7-point scale.
Similarly, interest in alternatives was measured using four items assessing fantasies, conversations, and flirtation with other people of the opposite sex. The researchers also collected information on sociosexual orientation, relationship length, and biological sex to account for individual differences that could influence sexual desire.
The second study, an experimental design, recruited 405 participants in long-term relationships through Amazon’s Cloud Research. The participants were randomly assigned to one of three priming conditions: they were either primed to experience sexual desire for their partner, primed to experience sexual desire for an alternative partner, or placed in a control condition in which they recalled non-sexual positive experiences.
The sexual desire primes asked participants to write detailed descriptions of situations that made them feel strong sexual desire for either their partner or another person they found attractive. Participants in the control group wrote about experiences that made them feel happy but not sexually aroused. After the priming task, participants reported their current sexual desire for their romantic partner and their desire for alternative partners on a 7-point scale. This experimental design allowed the researchers to assess whether activating sexual desire for one target (either the partner or an alternative) influenced desire for the other.
The results from the daily-diary study revealed a notable finding: on days when participants reported heightened sexual desire for their partner, they also reported greater interest in alternative partners. Conversely, on days when participants experienced stronger interest in alternatives, they expressed higher levels of sexual desire for their partner. This positive association persisted even after controlling for factors such as sociosexuality and relationship length, suggesting that sexual desire is not partner-specific.
In the experimental study, participants primed to feel sexual desire for an alternative partner reported significantly higher sexual desire for their romantic partner compared to those in the control condition. Interestingly, those primed with sexual desire for their romantic partner did not report a statistically significant increase in desire for alternative partners, though the results trended in that direction. The findings from both the daily-diary and experimental studies provided converging evidence that sexual desire is not exclusive to one’s romantic partner.
One limitation of the study was its reliance on self-reported measures of sexual desire, which could be influenced by social desirability bias. Future studies may benefit from using implicit measures to reduce potential biases in self-reporting.
The research, “Sexual Desire is not Partner-Specific”, was authored by Sierra D. Peters, Jon K. Maner, and Andrea L. Meltzer.
