One curious observation about human partnerships is that mates tend to match in terms of age, education, attitudes, and even physical attractiveness.

Sociologists and evolutionary biologists have long argued about how this happens, with theories falling into two camps. In one camp is the matching hypothesis. This is the idea that individuals somehow know how desirable they are and pick a mate at the same level.

In the other camp is the competition hypothesis. This assumes that everyone, regardless of desirability, seeks the most desirable partner. The result is that the most desirable people pair off, followed by the next most desirable, and so on.

These two hypotheses produce similar results from entirely different types of behavior. The only way to tease them apart is to study mating behavior in detail. That has always been too difficult to do on the scale necessary.

Today, that changes, thanks to the work of Elizabeth Bruch and Mark Newman at the University of Michigan, who have mined the data from a popular online dating site to break the deadlock. Their breakthrough is a new, objective way to measure desirability and to rank individuals accordingly.

The work provides a powerful new prism through which to view mating behavior. The researchers say it shows that competition for mates creates a pronounced hierarchy in desirability, and that both men and women consistently pursue partners more desirable than themselves. It also points to a simple strategy that could improve chances of success for most people.

First, Bruch and Newman’s objective method for measuring desirability: they say the most popular people are clearly those who receive the most interest on dating sites, as quantified by the number of messages they receive.

By this measure, the most popular individual in the study is a 30-year-old woman in New York, who received 1,504 messages during the month that Bruch and Newman conducted their study. “[That’s] equivalent to one message every 30 minutes, day and night, for the entire month,” they say.

But desirability is not just about the number of messages received but who those messages are from. “If you are contacted by people who are themselves desirable, then you are presumptively more desirable yourself,” say the researchers.

If this kind of approach sounds familiar, that’s because it is based on Google’s famous PageRank algorithm. This has been used to rank everything from web pages to Nobel Prize winners.

In this scenario, the PageRank algorithm provides an objective, network-based approach to rank men and women by their desirability. And having done that, it becomes straightforward to test the matching and competition hypotheses by monitoring whether people pursue mates with a similar level of desirability or not.

The results make for interesting reading. “We find that both men and women pursue partners who are on average about 25% more desirable than themselves,” says Bruch and Newman. “Messaging potential partners who are more desirable than oneself is not just an occasional act of wishful thinking; it is the norm.”

This approach is not without its pitfalls. The probability of receiving a response drops dramatically as the desirability gap increases. It’s easy to imagine that individuals who contact more desirable partners would do this more often to increase their chances of getting a reply.

“In fact they do the opposite: the number of initial contacts an individual makes falls off rapidly with increasing gap and it is the people approaching the least desirable partners who send the largest number of messages,” says Bruch and Newman.

So people obviously adopt different strategies for approaching potential mates with high and low desirability. Indeed, the researchers say individuals spend more time crafting longer, more personalized messages for more desirable partners—a quality-over-quantity approach.

The team also studied the content of these messages using sentiment analysis. Curiously, they found that women tend to use more positive words in messages to desirable men, while men use fewer positive words.

That may be the result of learning by experience. “Men experience slightly lower reply rates when they write more positively worded messages,” say Bruch and Newman.

Whether these different strategies work is far from clear. “The variation in payoff for different strategies is fairly small, suggesting that, all else being equal, effort put into writing longer or more positive messages may be wasted,” they say.

That’s interesting work, but it has less relevance for offline dating. Online dating offers a high volume of potential partners with a low threshold for sending a message, which is rather different from the offline world.

Nevertheless, the results provide some important insights. With regards to the matching and competition hypotheses, the evidence suggests that people use both. “They are aware of their own position in the hierarchy and adjust their behaviour accordingly, while at the same time competing modestly for more desirable mates,” say Bruch and Newman.

“Our results are consistent with the popular concept of dating ‘leagues,’ as reflected in the idea that someone can be ‘out of your league.’”

The findings also suggest an obvious strategy to attract a mate who is ‘out of your league.’ Bruch and Newman say that the chances of receiving a reply from a highly desirable partner are low, but they are not zero.

So the best strategy should be to send more messages to highly desirable partners and to be prepared to wait longer for a reply. “Messaging 2 or 3 times as many potential partners to get a date seems quite a modest investment,” say the researchers.

If anybody searching for a mate has some spare time, give it a try and let us know how you get on.

Ref: arxiv.org/abs/1808.04840 : Aspirational Pursuit Of Mates In Online Dating Markets