Émile Durkheim, the nineteenth-century French father of sociology, described the importance of having a balance between societal rules that are too strong or too weak. Without norms, he wrote, we enter anomie, a lawless state in which groups don’t cooperate and the goals of society and the individual begin to diverge.23 Lacking any guideposts for how to feel or what to do with their lives, people in a state of anomie are likely to commit anomic suicide, he speculated.

But when we break social norms, Durkheim explained, we are often punished socially as harshly as we would be under the law:24

If I do not conform to ordinary conventions, if in my mode of dress I pay no heed to what is customary in my country and in my social class, the laughter I provoke, the social distance at which I am kept, produce, even though in a more mitigated form, the same results as any real penalty.

When norms are too harsh, when society is too strict, Durkheim speculated that people feel “choked by oppressive discipline” and instead commit “fatalistic” suicide.25 (This idea of rampant suicide may sound very Victorian and melodramatic, but the fact that suicide rates are higher when society is either too libertine or too oppressive was found in a study just a few years ago.)26

Many social norms don’t necessarily make sense—what is the purpose of a necktie, for example, or of asking “How are you?” when you don’t really care—they just exist. Those who break them, even in benign ways, are known in the scientific literature as “deviants.” They bear all the baggage that word suggests.

There is, perhaps, no better representation of the randomness of social norms than swimwear. The entire process, from purchasing the bikini to donning the bikini to moistening the bikini to covertly picking the bikini out of your butt, entails specific, unwritten requirements that are hard to figure out yet unthinkable to violate. Forget literature; future anthropologists will study our pool selfies to gain knowledge of our ways.

Swimwear, if you think about it, is nearly identical to underwear. Consider the horror you would feel if someone walked in on you changing. Now consider the fact that all the women at the pool are wearing roughly the same amount of—or even slightly less—material than comprises their typical bras and briefs.

Yet we encourage this because…swimming.

Despite their skimpiness, there are elaborate rules women must adhere to when it comes to swimsuit shopping:

1. It can’t be an actual one-piece racing suit, like the kind Olympians wear. If you are fit enough to be a professional swimmer, the thinking seems to be, you should dress like you aren’t one.
2. The swimsuit must be revealing enough to perform your gender, yet modest enough to perform your age.
3. It must look like it could slip off very easily, while being unlikely to actually do so.