Helen S. Bateupa, Alan Boothb, Elizabeth A. Shirtcliff, Douglas A. Grangerc
Evolution and Human Behavior 23 (2002) 181–192
Hormone (testosterone, cortisol)–behavior relationships have been extensively studied among male competitors, and far less so among female competitors. To address this gap, we studied members of a nationally recognized college women’s rugby team. Seventeen players (ages 18–22 years) provided saliva samples 24 h before, 20 min prior to, and immediately after five league matches. Subjects selfreported aggressiveness, team bonding, pregame mental state, postgame performance evaluation, and whether the opponent was more or less challenging than expected. Results revealed that both testosterone and cortisol levels increased in anticipation of the matches. Postgame levels of both hormones were higher than pregame levels. The pregame rise in testosterone was associated with team bonding, aggressiveness, and being focused, but was unrelated to perceptions of the opponent’s skill. Testosterone change during the game was unrelated to winning or losing, evaluations of personal performance, or perceptions of the opponent’s threat. Game changes in cortisol were positively related to player evaluations of whether the opponent was more of a challenge than expected, and negatively related to losing. These results are compared with hormone–behavior patterns found among male competitors and are interpreted within a recent theory of sex differences in response to challenges.
In men, the relationship between testosterone and competition is reciprocal. Males characteristically experience a testosterone increase in anticipation of competition (Booth, Shelly, Mazur, Tharp, & Kittok, 1989). The precompetition rise is likely to make the individual more willing to take risks (Daltzman & Zuckerman, 1980), improve psychomotor function and coordination (Herrmann & Beach, 1976), and increase cognitive performance (Herrmann, McDonald, & Bozak, 1976; Klaiber, Broverman, Vogel, Abraham, & Cone, 1971; Vogel, Broverman, Klaiber, Abraham, & Cone, 1971). For a few hours following competition, testosterone is high for winners relative to losers (Booth et al., 1989; Elias, 1981; Mazur & Lamb, 1980). The rise in testosterone following a win is associated with positive mood (Booth et al., 1989), and is thought to be important because winners often face challenges from others soon after gaining new status.
(Cortisol is a steriodal hormone that the body produces in response to stress)
The increase in women’s testosterone in response to a game was unrelated to winning or losing or to the evaluation of personal performance. Two factors were related to the cortisol rise during the game: (1) the extent to which the opposing team was more challenging than expected (something not studied in men) and (2) whether the team won or lost. Players who reported the opponent to be more challenging than expected experienced a mean rise in cortisol of 46 percentage points. When the opponent played at the level of skill expected, cortisol rose by 26 percentage points, whereas it increased by only 8 percentage points when the opponent was not as challenging as expected. In short, the greater the challenge experienced by the players during the game, the greater the increase in cortisol levels
[F(49) = 4.378, P=.04]. When the team lost, cortisol levels rose 0.34 mg/dl, whereas they only increased by 0.14 mg/dl if they won [F(49) = 3.973, P=.03]. The latter finding differs from those in studies of men. Elias (1981) found that, compared to losers, winners’ cortisol increased. Booth et al. (1989) found no relationship between cortisol change during the game and winning and losing.
(Also of interest is the observation that following a win the rugby players did not experience the testosterone-related elevation in positive evaluations of performance often observed in male competitors. Nor did the losers experience the decline in testosterone experienced by men. Rather, women who won experienced a very modest increase in cortisol compared to a relatively large increase among those who lost. These findings are consistent with Taylor et al. (2000) suggestion that females’ responses to challenges are more likely to be directed toward creating and maintaining relationships. Competition, especially that which is physically aggressive, has the potential to threaten old relationships and prevent the creation of new ones. Lower cortisol associated with winning suggests that females are managing the challenge of competition effectively so that high cortisol levels do not interfere with the conciliatory behavior that restores potentially beneficial relationships with individuals who were opponents a few moments earlier and teammates who were challenged in the heat of the competition. These women may very well be on the same team in all-star games; under such circumstances, they could not carry over animosity from earlier games in which they had been opponents.)
Men and women also share a precompetition rise in cortisol, but its bearing on performance is unclear. There are several differences. For one, men’s pregame cortisol is related to skill and experience—more talented competitors have lower cortisol (perhaps related to more effective stress management) than less-skilled men, something not found in women. Furthermore, men and women differ in their hormonal response to winning and losing. Many, but not all, male winners experience an increase in testosterone (correlated with elevation in positive evaluations of performance), while losers show a decline in the hormone. While women experience a rise in testosterone during competition that is greater than men’s, it is unrelated to either self-evaluation of performance, or winning and losing. On the other hand, changes in cortisol are related to the outcome of the contest: female winners have lower cortisol than do losers, something that does not occur among men.
It is possible that team participation rather than sex differences in biobehavioral response to stress are the key to understanding our results. It is important to keep in mind that the majority of hormone–competition studies involve sports that stress individual performance (e.g., tennis, judo, wrestling, racket ball, chess) more than team efforts. In a team, an individual’s status may be more strongly tied to the social interaction within the group than to the outcome of a particular contest. One-on-one competition may have a more direct impact on individual status and, therefore, on the testosterone response to winning and losing. Further studies of team sports will clarify this caveat.