Flirting is exhausting. It requires you to control your behaviour (‘Don’t act like a moron!’), monitor the impression you are making (‘Are we laughing at the joke or at me?’) and communicate on several different layers (‘Do you want to come up for tea?’). No wonder men’s cognitive performance is worse afterwards. Surprisingly though, the exhaustion sets in a lot earlier already: before men even know who the woman may be.
Nauts and colleagues have a (freely available) article in press at the moment which looks at the cognitive performance of men and women as a result of being observed by an unknown male of female experimenter. In a first experiment, they asked participants to read words out loud while either ostensibly being monitored by ‘Bas’ (a fake male experimenter) or ‘Lisa’ (a fake female experimenter). Importantly, participants only knew the names of their observers. They never saw them or directly interacted with them. It must have looked like your typical unsexy psychology experiment in which boredom is the unmeasured main effect.
Before and after reading words out loud, people performed a Stroop task. Basically, it asks you to name the ink colour of coloured colour words, e.g. people are quite fast on RED, GREEN, and BLUE but usually slower on RED, GREEN, and BLUE. This difference is sometimes taken as an indicator of people’s ability to overcome an easy, fast response due to attention on the word meaning. As predicted, men’s Stroop performance was significantly worse after having been ‘observed’ by ‘Lisa’ compared to ‘Bas’, i.e. their cognitive performance on a standard control task was worse just because they felt that a completely unknown woman (they would likely never meet) had a look at their mouth while pronouncing words.
In a follow-up experiment participants were told about the upcoming word reading task – and the gender of the experimenter who would observe them – already before the Stroop task was performed for the first time. As predicted, men’s Stroop performance was somewhat worse when merely expecting to be observed by an unknown female experimenter compared to a male one . This suggests that the preparation for being observed by a woman is enough to cognitively exhaust men.
Interestingly, in neither experiment women’s cognitive performance was affected by the gender of the previous (Experiment 1) or upcoming (Experiment 2) observer. Mind that the statistical power was greater for women given that more were tested. In other words, the experiment was more likely to find a female participant effect than a male participant effect. The authors suggest that women are generally more selective in terms of seeing a situation as flirtatious or not. Men on the other hand, well, are less selective.
So, the exhaustion of flirting appears to start even before the flirt, or even before a situation which could possibly lead at some point to a flirt. While the authors are right in writing that a replication with homosexual participants would be interesting, the far more obvious short coming lies elsewhere.
Nauts et al. did not just test ‘men’ and ‘women’ but 21 year old students. To put it more bluntly, they arguably recruited the most horny people on campus. So, this study is not just an example of young men’s readiness to expand cognitive resources on a completely unlikely mating partner. It is also an example of the need for Psychology to go beyond student samples in order to truly reveal something about human nature.
Nauts, S., Metzmacher, M., Verwijmeren, T., Rommeswinkel, V., & Karremans, J. (in press). The Mere Anticipation of an Interaction with a Woman Can Impair Men’s Cognitive Performance . Archives of Sexual Behavior. doi: 10.1007/s10508-011-9860-z
 A one tailed test with a p-value of p=.04 should be taken with a pinch of salt.