So what? What can we glean from this motley bunch of citations? What's the moral of the story?

Perhaps the most important moral is that sexuality, however subtle, is not trivial. If you don't want to deal with sex or relationships or in-laws, fine, you can abstain; on the other hand, there's no clear way to entirely avoid these many strange influences of sexual motivation. Think of the effects in terms of "mental contamination", which Wilson and Brekke (1994) define as "the process whereby a person has an unwanted judgment, emotion, or behavior because of mental processing that is unconscious or uncontrollable. By unwanted, we mean that the person making the judgment would prefer not to be influenced in the way he or she was…" (p. 117) Psychological research tells us that our lives are teeming with mental contamination of all sorts. As Wilson and Brekke point out, correcting for mental contamination is no small feat: one must be aware that the contamination exists in the first place, motivated to correct for it, cognizant of the direction and magnitude of the bias (or else one might overcompensate, or compensate in the wrong direction), and able to change one's behavior appropriately. The weakness of human introspection (Nisbett & Wilson, 1977) implies that this is, in practice, impossible. And thinking that mental contamination poses no threat to you might make the problem worse. In Study 3 of Nordgren, van Harreveld, and van der Pligt (2009), smokers led to believe they had better self-control accepted greater temptation in a self-control game (for a greater monetary reward) and were more likely to lose the game. Study 4, a nonexperimental 4-month longitudinal study, examined smokers who'd just quit. Smokers with greater self-control beliefs didn't avoid temptation as much and were more likely to relapse. I'd speculate that, similarly, trivializing mental contamination could make you complacent about it, making you more likely to expose yourself to sources of it and thereby aggravate the harm.

The worst-case possibility can be caricatured as follows: sexual feelin's make you careless, impatient, stupid, and violent, and the most you can do about it is avoid sex cues, and good luck with that in the world we live in.

But actually, before we even try to avoid or compensate for these influences, we might ask whether they are, in fact, bad. After all, whereas some of the effects seem clearly undesirable, like increased aggression, and some are of dubious value, like altered time perception, some seem beneficial, like increased generosity. The truth is that while psychology experiments are excellent for identifying the motivational forces underlying behavior and what directions those forces push people in, they're poorly suited to quantifying the real-life consequences of those forces, and such quantification is what we need for real-life decision-making.

Imagine, for example, that the executives at some business, upset with the underrepresentation of women among their employees, decide to recruit women more aggressively, and they succeed in balancing the sex ratio. We can expect that this change will make the male employees a bit more aggressive and a bit more generous. But how will these changes compare to each other in magnitude? And is it possible that the aggression could be ultimately good for the business (by making the men more effective salesmen) and the generosity be ultimately bad (by making the men too eager to make sacrifices)? And how will the effects of the women on the men compare to the effects of the men on the women? If the executives were deciding whether to recruit more women to begin with, and they wanted to meaningfully apply the research I've discussed in this chapter, they'd need to be able to estimate answers to these questions (not to mention weigh these concerns properly against all other relevant concerns, from ethics to tax consequences). And in order to make such estimates, they'd need much fancier research than what exists now. For starters, they'd need explicit statistical models of the effects of arbitrary sex cues on arbitrary behavior. That's the kind of sophistication that I doubt psychology will achieve in my lifetime.

Anyway, the point of this thought experiment is: it's not totally clear whether the odd consequences of sexual motivation are good or bad for the human race, and it won't be totally clear anytime soon. In the meantime, I have a few suggestions. Don't hang up swimsuit calendars in offices. Dress modestly in public. And be wary of the idea that sex is necessarily good.