Does This Make Me Look Fat? The Ultimate Nash Equilibrium

It's Saturday night and you're waiting for your girlfriend Sarah to finish getting ready. Sure, you were ready to grab dinner and hit the bar fifty minutes ago, but one room away, life or death decisions are being made. Sarah doesn't know what to wear. Are jeans and a T-shirt too informal? Do I want to walk around in heels all night? When was the last time I wore pink?

And that's when she hits you with it. "Does this dress make me look fat?"

Now, to the uninitiated in microeconomics (specifically, game theory), this seems like a fairly innocuous situation. Just tell Sarah she doesn't look fat; in fact, tell her she looks absolutely stunning in that disgusting bright green dress she just grabbed. No matter what it takes, just get her dressed, happy, and most importantly, out the door already.

After studying microeconomics, however, it dawns on you that the exchange you and Sarah just had is fundamentally rooted in game theory! See, this isn't the first time Sarah has pulled this self-esteem inflating maneuver. Every time she asks if something she wants to wear makes her look fat, and every time you respond by dousing her with compliments. This is no coincidence.

Once Sarah starts the game, you have two options: A) Truth or B) Lie. Sarah has two potential responses: A) Happiness or B) Wrath.

Therefore, the four possible scenarios play out as follows: If you select scenario A), half the time you will truly like what Sarah is wearing. After all, she's your girlfriend--you probably find her attractive on some level. This brings both of you your highest enjoyment. For example's sake, we'll say this generates 100 happiness for you, and 100 happiness for her. But, another percentage of the time you will think she looks disgusting, and you while you will be happy and receive minor utility for telling the truth, Sarah can pretty much assure the rest of your night will be a living hell. Levels of enjoyment could be 20 for you, and 0 for Sarah. Lying isn't fun, so selecting scenario B, lying to keep Sarah happy, probably isn't as fulfilling as if you had actually meant your compliments, but Sarah assumes you mean it, so lying could yield 80, 100 in happiness. (A fourth example exists where you like what Sarah is wearing but lie and say she looks ugly in it, but this is irrational, and thus, discounted).

Now, believe it or not, boyfriends do not want to lie. Lying is not fun. It can create stress, pressure, and most importantly, the chance to get caught lying. So, I would argue that if it weren't for her reaction, the gains from telling Sarah the truth about her gross attire, having her change, and then leaving for your evening plans should equal the happiness of honestly believing she looks gorgeous in her current dress.

But, as men, we know in advance how Sarah is going to react and we want no part of it. Assuming we hate what she's wearing, our options are either happiness of 20 or 80. There is no way for us to be totally happy -- ugh, she's wearing that dress -- but we're not crazy. We'll lie and take the 80 happiness, thanks. And thus, Nash Equilibrium is achieved.

Unfortunately, women also know this equilibrium exists. They know you have to compliment them. And that's why boyfriends the world over have to hear the question "Does this dress make me look fat?" over, and over, and over, and over.... again.