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Persistence is an important predictor of future successes. The present research addresses the relationship between testosterone and persistence in men. One hundred eighteen men were randomly assigned to win or lose a competitive number tracing task against a confederate or complete the task alone in a non-competitive control condition. Saliva samples were collected prior to and after the competition or control conditions. Participants were then given a maximum time of 30 min to spend attempting to solve unsolvable puzzles, with the option to quit at any time. In contrast to our prediction, changes in testosterone concentrations in response to the competitive interaction did not predict persistence behaviour. However, individual differences in testosterone concentrations (pre-competition/non-competition) were positively correlated with persistence. These findings are the first to examine associations between neuroendocrine function and persistence behaviour in people and suggest that testosterone should also be considered when predicting persistence-related outcomes. Copyright © 2014 European Association of Personality Psychology
Stephen King's first novel, Carrie, was rejected repeatedly by publishers prior to its initial publication in 1973. After the 30th rejection of the book, Stephen King threw the manuscript in the trash, but again resubmitted it for publication at his wife's recommendation. From childhood, Stephen King submitted many short stories to publishers and magazines, which were ultimately rejected. All of the rejection letters he received were hung on a nail on the wall. By the time he reached the age of 14 years, the nail no longer supported the weight of all the rejection slips, so he replaced the nail with a large spike and continued writing (King, 2000).
Aside from sheer luck, persisting in the face of obstacles, failures and rejection is an important route in gaining higher status and achieving goals. By definition, persistent individuals are less likely to submit and give in to obstacles in their path to achievement. A popular belief in western society is that hard work and perseverance can lead to upward social mobility and increased status (e.g. Furnham, 1989; Weber, 1905). Accordingly, being persistent can lead to increased academic success (Reardon, Arshan, Atteberry, & Kurlaender, 2010), creativity (McKeown & Lindorff, 2011) and greater likelihood of employment (Shalley, Zhou, & Oldham, 2004), among other important successes.
Why do some individuals persevere in the face of failure, adversity and repeated rejection when others do not? Researchers have examined many explanations of human persistence behaviours, including self-control (e.g. Barber, Grawitch, & Munz, 2012; Baumeister, Bratslavsky, Muraven, & Tice, 1998), having a low-level construal (e.g. Agrawal & Wan, 2009), previous positive evaluations (Reardon et al., 2010), increased intrinsic motivation (e.g. Shalley et al., 2004), conscientiousness (Duckworth, Peterson, Matthews, & Kelly, 2007) and temporal expectations (McGuire & Kable, 2012).
In addition to these factors, testosterone could be one predictor of persistence behaviours. Endogenous testosterone concentrations are linked to dominance and aggressive behaviours in nonhuman animals (e.g. Beehner, Bergman, Cheney, Seyfarth, & Whitten, 2006; Gould & Ziegler, 2007; Wingfield, Hegner, Dufty, & Ball, 1990). Additionally, experimental and correlational research in nonhuman animals (specifically, chicks, rats and mice) suggests that testosterone increases basic forms of persistence behaviour, measured as persistence in searching for food and social investigation (Andrew & Rogers, 1972; Archer, 1977; van Hest, van Haaren, & van de Poll, 1989; Thompson & Wright, 1979; Thor, 1980). This experimental work has comprised injecting testosterone into either immature animals (Andrew & Rogers, 1972), castrated adults (Archer, 1977) or non-castrated adults (Thompson & Wright, 1979).
Will higher levels of endogenous, baseline1 testosterone concentrations lead to higher levels of persistence within humans? Meta-analytic evidence suggests that baseline testosterone concentrations show a positive, yet weak, relationship with dominance behaviours, particularly aggression, in humans (Archer, Graham-Kevan, & Davies, 2005). However, context-dependent changes in testosterone have been thought to be more strongly correlated with aggression (see Carré, McCormick, & Hariri, 2011 for a review), and to fine-tune dominance-related behaviour (Mazur, 1985). Men's testosterone concentrations generally fluctuate in response to winning or losing a competition, with testosterone decreasing in losers and remaining elevated in winners (Archer, 2006; Carré, Campbell, Lozoya, Goetz, & Welker, 2013). These changes in testosterone after competitive outcomes have been found to map onto future dominance behaviours, such as reactive aggression (Carré et al., 2013), willingness to compete with others (Carré & McCormick, 2008) and the desire to compete with others again after a competitive defeat (Mehta & Josephs, 2006). Thus, in addition to individual differences in ‘baseline’ testosterone concentrations, it may be critical to examine the extent to which testosterone reactivity to competitive interactions predicts persistence behaviours.
Although baseline testosterone and testosterone reactivity predict dominance and desire to compete, they also may predict persistence behaviours in men. The goal of this study was to examine if baseline testosterone, competitive outcomes and testosterone reactivity would predict persistence behaviour in men. We hypothesized that baseline testosterone would be positively related to persistence behaviour. We also hypothesized that competitive outcomes and testosterone reactivity to these competitive outcomes would predict persistence behaviour. Similar to Carré and colleagues (2013), this hypothesis holds that winners would show an increase in testosterone that would in turn be associated with greater persistence, whereas losers would show decreases in testosterone that would be associated with less persistence. However, on the basis of the work by other researchers (e.g. Mehta & Josephs, 2006), we also considered the possibility that variability in testosterone reactivity within winners and losers may predict persistence as well. To test these hypotheses and aims, the present research randomly assigned men to win or lose a competition with a confederate, or complete the competitive task alone, with salivary testosterone measured before and after the task. Then, as a measure of persistence, participants were timed at how long they persisted in attempting to solve puzzles with no possible solution.
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The present research found that baseline testosterone concentrations predicted persistence on unsolvable puzzles in men. This is the first research to suggest that testosterone predicts persistence behaviour in men. These findings have implications for the link between testosterone and dominance, suggesting that high testosterone men are less likely to quit in the face of challenging task. Given the importance of persistence in accomplishing career and academic successes (McKeown & Lindorff, 2011; Reardon et al., 2010; Shalley et al., 2004), testosterone may be a useful predictor of whether individuals strive for higher social status through increased persistence. However, the causal direction of this relationship is unclear.
A wide range of literature suggests that testosterone reactivity can be modulated by competitive outcomes such as those of video games (Carré et al., 2013) and athletic competitions (see Archer, 2006 for meta-analysis). The current study used the NTT, which has been used in multiple studies examining relationships between hormones and competitive behaviour (e.g. Mehta & Josephs, 2006; Schultheiss et al., 1999). Although both Schultheiss and colleagues (1999) and Mehta and Josephs (2006) did not find that the NTT outcomes affect testosterone reactivity, Schultheiss and colleagues (1999) did find, however, that the effect of the NTT outcomes on testosterone reactivity is moderated by implicit power motive. On the other hand, Mehta and Josephs (2006) find that desire to compete again following a competitive loss is predicted by testosterone reactivity in losers. To the extent that choosing to compete again after a competitive loss is a measure of persistence behaviour—we expected to find a similar association in the current study. We suggest that it is possible that individual difference factors (e.g. power motive; Schultheiss et al., 1999) may play a key role in moderating the effect of testosterone reactivity on subsequent persistence behaviour. Future research will be required to test this possibility. On the basis of these findings and the current research, the relationship between testosterone reactivity and persistence may not occur in the manner of Carré and colleagues' observed effects of testosterone reactivity on aggressive behaviour (2009, 2013), but instead may be modulated by individual differences or specific competitive outcomes.
The current research did not find that testosterone reactivity to competitive outcomes predicted persistence. However, it is important to note that this may be due to the failure of the NTT to produce testosterone reactivity to competitive outcomes. Thus, it is possible that other researchers may find effects of testosterone reactivity on persistence using research paradigms that are potentially more robust modulators of testosterone reactivity than the NTT such as video game competitions (e.g. Carré et al., 2013) or aggressive provocation (Carré, Iselin, Welker, Hariri, & Dodge, in press). It is also possible that longer durations of testosterone reactivity assessment, occurring 15–20 min after the win or loss manipulation, may capture effects of testosterone reactivity from winning and losing the NTT. This possibility is unlikely, however, as previous work using the same task has reported decreases in T in male winners and losers when T concentrations were measured 15 min after the competition (Mehta & Josephs, 2006).
The current work features the largest known sample size used studying competitive outcomes and testosterone reactivity with the NTT and is the most adequately powered to test the effects of competitive outcome on testosterone reactivity. On the other hand, robust main effects of competitive outcome on testosterone reactivity have been observed in athletic competitions (e.g. Archer, 2006) and motion-controlled video games (Carré et al., 2013). It is possible that certain individuals are not as motivated to win the NTT compared with other competitive interactions, or that physically engaging tasks more robustly affect testosterone reactivity.
One limitation of the current research is that it did not measure whether individuals were sensitive to whether the puzzle task was unsolvable or not. Previous researchers have distinguished between productive persistence—persistence resulting in success—and self-defeating non-productive persistence—persistence resulting in frustration and wasted effort (e.g. Baumeister & Scher, 1988; McFarlin, Baumeister, & Blascovich, 1984). In particular, there are several individual differences that predict whether individuals engage in non-productive persistence, such as self-esteem (McFarlin, 1985), optimism (Aspinwall & Richter, 1999) and self-mastery (Aspinwall & Richter, 1999). In addition to measuring whether participants realize the puzzles are unsolvable, researchers of the relationship between testosterone and persistence may want to take these predictors into account.
A second limitation of the current study is that this work did not include a sample of women. The extent to which testosterone reactivity and/or baseline testosterone concentrations predict persistence behaviour in women is not clear. Previous work indicates that relationships between testosterone reactivity and aggressive behaviour in women are small and nonsignificant, compared with men (e.g. Carré et al., 2009, 2013). However, other research indicates that baseline testosterone concentrations in women can predict competitive performance (Mehta, Wuerrhman, & Josephs, 2009) and decision making (Mehta, Jones, & Josephs, 2008). Previous work suggests that women are more prone to distraction on an attentional task compared with men, (Stoet, 2010). To the extent that persistence is negatively related to distraction (as suggested by research in animal models), we may predict that individual differences in testosterone may also underlie one's ability to resist distraction and persist towards a goal/reward (e.g. solving a difficult puzzle). Thus, it will be important for future work to examine the extent to which men and women differ in their persistence behaviour on the puzzle solving task, and whether variation in testosterone concentrations partially mediate the effect.
Although the correlational nature of the relationship between baseline testosterone concentrations and persistence limits our ability to make strong causal claims, the reported relationship suggests that high testosterone may contribute to persistence behaviour—a key factor involved in the attainment of social dominance. However, it is important to note that despite the observed relationship between testosterone and psychological dominance (Archer et al., 2005), high testosterone males have been found to hold lower occupational statuses (Dabbs, de la Rue, & Williams, 1990). Although persistence may be a status-seeking behaviour, not all persistence behaviours may actually result in increased status. For instance, in the face of obstacles, some individuals may persist antisocially (e.g. pestering a rejecting employer and harassing a former romantic partner after rejection), whereas others may not persist antisocially (e.g. continuing to apply to other jobs and seeking out a different partner). Therefore, future research is needed to determine moderators and predictors of whether individuals will persevere prosocially or antisocially, and whether persistence is likely to result in success.
Additionally, future work is needed to investigate the potential moderating role of social context in these findings. Previous work suggests that basal testosterone is associated with decreased cognitive performance when social contexts are cooperative in nature (Mehta et al., 2009). This concept is supported by work demonstrating that testosterone decreases cooperation by promoting egocentric decision making (Wright et al., 2012). The present study suggests that basal testosterone is positively associated with persistence behaviours, but these findings occur in the context of a competitive task. Thus, it is possible that testosterone may be inversely related to persistence when in the context of collaborating with others. Relatedly, if participants were also informed that the persistence task was indicative of how individuals work well with others, testosterone may be negatively associated with persistence on this task.
Broadly, the construct of persistence also needs to be further developed by researchers. Although this study assessed persistence on a puzzle task, other researchers of persistence behaviours have operationalized persistence in other ways, such as the extent to which chicks search for food (Andrew & Rogers, 1972), individuals' perseverance and passionate for long-term goals (Duckworth et al., 2007), maintaining performance over long periods of work (Johnson & Layng, 1992) or time spent solving mathematics puzzles (Battle, 1965). On the other hand, it is also possible that assessments of distractability (e.g. Stoet, 2010) also capture the absence of persistence. The results of this study show that men's baseline testosterone concentrations predict one of these operationalizations of persistence. However, given that testosterone is broadly thought to be related to a host of status-seeking behaviours (Eisenegger, Haushofer, & Fehr, 2011; Mazur, 1985; Mazur & Booth, 1998; Mehta & Josephs, 2006; Wingfield et al., 1990), testosterone may indeed be related to other forms of persistence, such as to acquire resources (e.g. money or employment) or academic achievement.