Online dating has become the second most common way for couples to meet, but it may encourage a "shopping" mentality in which people become judgmental and picky, focusing exclusively on a narrow set of criteria like attractiveness or interests, says a new study.

The analysis, based on a review of more than 400 psychology studies and public interest surveys, was released online Monday ahead of being published this month in the journal Psychological Science in the Public Interest.

"The internet holds great promise for helping adults form healthy and supportive romantic partnerships, and those relationships are one of the best predictors of emotional and physical health," said Harry Reis, one of the five co-authors of the study and professor of psychology at the University of Rochester.

Your News Do you use online dating sites? What are the pros and cons? Email us at yournews@cbc.ca

Online dating has grown rapidly in popularity and social acceptance and is second only to meeting through friends, as a way for singles to connect, but it does have its pitfalls, Reis said.

Comparing dozens and sometimes hundreds of possible dates may encourage a "shopping" mentality in which people focus on a narrow set of criteria like attractiveness or interests, he said. And corresponding by computer for weeks or months before meeting face-to-face has been shown to create unrealistic expectations, he added.

"In the words of one online dater: 'Where else can you go in a matter of 20 minutes [and] look at 200 women who are single and want to go on dates?'"

Among the study's other findings: