Salivary testosterone samples were obtained from a sample of men and details about their relationship status, sociosexual orientation, extra-pair sexual interest, and their perceptions of their relationships were recorded. A study in Psychoneuroendocrinology found testosterone levels increased by 35 percent after watching a sexually explicit film. Single and casually partnered men had significantly higher testosterone than those in committed relationships. The findings revealed transitioning from a committed to non-committed relationship status predicted an increase in testosterone. The men also reported their number of sexual/relationship partners for each relationship status. However, studies have not clarified these links; whether testosterone levels predict relationship status or whether relationship status predicts testosterone. Researchers at the University of Michigan, Ann Arbor found testosterone levels predicted relationship status a month later, and testosterone also responded to changes in relationship status. They hope to examine how specific types of relationship transitions are linked to testosterone. The researchers do caution results may be different in older men, and those with different types of relationship statuses and experiences. This is consistent with previous research that has linked lower testosterone to monogamy in men, while high testosterone is linked to singlehood, or a lack of nurturing behaviors. The participants completed a series of questionnaires, including those related to their relationship status. The researchers hypothesized this college transition would be a crucial time for relationships, where casual and committed relationships becoming prevalent among first-year college students. However, as research increases our understanding of the different factors involved, including the contribution of the present study in terms of "new relationships," the picture is becoming clearer. No significant correlations were found between levels of testosterone and any SOI measure or age (see Table 1). Salivary levels of testosterone were analyzed in duplicate using enzyme-linked immunosorbent assays according to the manufacturer's instructions (Salimetrics, 2014). Other studies have taken relationship length into account, but only in terms of either excluding men in new relationships (e.g., Gray, Campbell, Marlowe, Lipson, and Ellison, 2004) or by only concentrating on changes in relationship status over a 6-month period (van Anders and Watson, 2006). This has the advantage of avoiding attaching broad labels to the relationship type a man is in, meaning it can be more precise than categories such as "casually dating." In a similar vein to being in "casual relationships," it was expected that men in "new relationships" would not have experienced the adaptive decrease in testosterone of men in longer relationships. Although this is important, as it should accurately reflect their subjective belief about the relationship (thus revealing their underlying psychological state with regards to their current motivation to seek new partners), it may not be wholly accurate. One potential limitation of these findings with regards to relationship type is that it relies on self-categorization by participants (e.g., Burnham et al., 2003; Gray, Chapman, et al., 2004; Sakaguchi, Oki, Honma, and Hasegawa, 2006; van Anders and Goldey, 2010; van Anders et al., 2007; van Anders and Watson, 2006). There also may be a connection between relationships and your testosterone levels. Furthermore, even though there was found to be significant differences between the different relationship types, no significant correlation was found between relationship length and levels of testosterone (however, it is worth noting from Figure 1 and the reported correlation size that this may be partly due to the sample size). This perhaps reflects that the internal psychological mechanism that mediates changes in the levels of testosterone in men in relationships is a complex one, and difficult to measure when using external indicators of "commitment" (be it marriage, fatherhood, or length and/or type of relationship). Similarly the negative effect that age can have on testosterone levels (e.g., Harman, Metter, Tobin, Pearson, and Blackman, 2001) is also not responsible for these differences, as there was no significant difference between the ages of participants in the different relationship categories. This suggests that the psychological change in motivation to compete (and with it, the subsequent drop in levels of testosterone) tends not to have occurred for those in new relationships. A total of 79 male first-year college students were recruited for the study to explore monthly changes in testosterone and relationship status as they transitioned to college. In the new study, published in Adaptive Human Behavior and Physiology, van Anders and her colleagues sought to clarify these links by investigating how behaviors can affect hormones. Researchers from the University of Sunderland and the University of Worcester found men in long-term relationships for more than a year tested lower for testosterone than single men or men in new relationships. Also, men in polyamorous relationships (with multiple committed partners) have greater levels of testosterone than those in monogamous relationships (Gray, 2003). Similarly, only paired individuals with a more restricted sociosexuality had low testosterone levels, and paired men with a higher desire for uncommitted sexual activity had testosterone levels that were similar to those of single men (Edelstein, Chopik, and Kean, 2011). Higher levels of testosterone can even make it easier for people in committed relationships to show their feelings openly and securely without feeling uncomfortable or embarrassed about expressing themselves. A 2015 study found that single men and men in new relationships had higher testosterone levels than men in long-term relationships. In other words, it may be that men with higher baseline levels of testosterone are more likely to terminate their relationships before they become long-term due to their greater propensity to seek new partners (van Anders et al., 2007). Also the lack of a difference in terms of levels of contact with partners suggests that physical proximity is not the mechanism by which men in relationships experience lower levels of testosterone, as van Anders and Watson (2007) also found. To identify whether levels of testosterone varied between the relationship categories, a univariate ANOVA was conducted, with levels of testosterone as the dependent variable and relationship status (single vs. new relationship vs. paired) as a between-subjects measure. It was predicted that long-term paired men would have lower levels of testosterone than both single men and men in new relationships, whereas there would be no difference in levels between men in these latter two relationship categories. And, what to do if you suspect your testosterone levels are low. Here’s a look at the relationship-testosterone link, specifically how being in a relationship could affect your levels and how low testosterone might affect your relationship. A final consideration of these findings is that it has recently been shown, since the current study was executed, that saliva assays for testosterone are affected by the use of sugar-free chewing gum (van Anders, 2010). Interestingly, the median of 12 months from this sample population coincidentally would also correspond to a major landmark that men may recognize (i.e., a full year in the relationship is often acknowledged by both partners and others as an anniversary and an important milestone). This issue of cause and effect in the link between male mating strategy and testosterone levels is common to much research in this area and may only be fully resolved in future studies that utilize extensive longitudinal research.
