PSYPOST – Tinder’s early expansion across U.S. colleges increased the number of sexual partners among fraternity and sorority students but did not lead to more committed relationships, according to a study of 1.1M students published in the American Economic Journal: Applied Economics. Researchers also linked Tinder’s introduction to a two-percentage-point rise in reported sexual assaults, more chlamydia cases and increased HIV testing. Average mental health did not worsen, with some female students reporting modest improvements.