Looking for a partner on the Internet is no longer a rarity.

Millions of people are searching online for a flirt or even true love. A study presented in the journal "PLOS One" examined how they behave in this process. The researchers ranked users of a Czech dating app according to their desirability – based on the number of expressions of interest, or swipes, they received from the opposite sex.

They found that, on average, men were more likely to contact women who were more desirable than themselves. Women were more likely to target men who were at a similar or slightly lower level than themselves. A match, i.e. a mutual encounter, occurred predominantly in couples where both sides were rated as similarly desirable.

So does the old saying "birds of a feather flock together" hold true? The researchers hypothesize that existing preferences play less of a role here than the overall process. This pattern is predominantly the result of rejections by the more desirable partner and not the result of an initial preference for similarity, they note.

The team comments that successful matches are more in line with women's preferences than with men's. "This likely reflects women's stronger position in the online dating market, as men outnumber women and are often expected to make the first move."

The author duo Renata Topinkova from the Ludwig Maximilian University of Munich and Charles University in Prague, as well as Tomas Diviak from the University of Manchester in the UK, analyzed data from a Czech dating app collected anonymously in July 2017. They evaluated information from 2,321 users in Prague and 624 from the second-largest city, Brno. The team acknowledges that further research is needed, for example, on other apps with more sophisticated algorithms. This is all the more important given that more and more couples are meeting online through dating apps.

The app analyzed has significantly more men than women, meaning women receive more swipes on average. "We take this into account statistically so that our results aren't distorted by the imbalanced ratio between men and women," explained researcher Topinkova. "Specifically, we standardize all results based on the number of users of the opposite sex."

The dating app examined did not collect any information about users' motivations. "However, this can vary greatly – from looking for a one-night stand to the desire for a long-term relationship," the team admits in the study.