> ...buying something useless and expensive is a very strong signal...
I see this comment every time engagement rings come up on Hacker News. Yes, it's a strong signal. But we're a bit smarter than that, and we can select mates who are smarter than that too. Perhaps this kind of peacocking will die out. Perhaps nature will select for mates who are level-headed enough to look at salary figures rather than shiny rocks. There are going to be a lot of people who realize that a down payment on a house or money in the bank will make their relationship more successful than a shiny rock will. I'm willing to bet on those people living and reproducing.
Right... but humans have a much richer way of signaling than most animals. My point is that some humans will find ways to signal commitment without sinking three months of their salary into a worthless rock. Signalling theory is an explanation for observed behavior, not a guarantee that such behavior will persist if the organisms in question develop alternative strategies.
I like to think humans are pretty good at developing alternative strategies.
Besides, if you get divorced, you don't get your down payment back anyway.
Sure, as I said in another comment, diamonds could probably be replaced. But it would probably be by something just as useless.
Or maybe if you can find a way to mimic the effect, but make it useful, you have your hands on a very valuable startup idea.
I guess it would be something like helping friends move, which is considered a good signal for true friendship. I don't know (not an expert on this), maybe if you find a way to "help your spouse move" for the equivalent worth of 3 months of your salary, you are good.
Why don't you get your down payment back if you get divorced?
The point is, changing spouses is expensive if they all want a diamond ring. So that custom is a shield against heavy spouse changing.
The whole marriage thing is also extremely expensive. I suspect for similar reasons - so that people think twice before throwing it away. In that case they also have angry friends and relatives who invested into expensive travel and presents and probably wouldn't be too happy if it was all for nothing.
There are only a few outliers, by definition. So most people have to make the compromise. Coordination games work by punishing you when you don't follow the crowd.
I see this comment every time engagement rings come up on Hacker News. Yes, it's a strong signal. But we're a bit smarter than that, and we can select mates who are smarter than that too. Perhaps this kind of peacocking will die out. Perhaps nature will select for mates who are level-headed enough to look at salary figures rather than shiny rocks. There are going to be a lot of people who realize that a down payment on a house or money in the bank will make their relationship more successful than a shiny rock will. I'm willing to bet on those people living and reproducing.