Many people believe in love at first sight, but new research suggests that love on second sight may be a likely effect of speedy swiping on Tinder, the popular dating app. And that may not be such a good thing, as one's perceptions can be biased by the previously swiped prospect.

Tinder, Bumble, Skout and other dating apps have changed the dynamics of how young people look for relationship partners. It's a phenomenon that society at large is still coming to grips with, even as using an app like Tinder has become not only acceptable, but even commonplace, among the smartphone generation.

Several psychologists who have looked into the dating app craze have spoken supportively of the practice. Tomas Chamorro-Premuzic of University College London says that Tinder-style dating simply reflects current lifestyles and worldviews. "People are time-deprived, careers have priority over relationships, not least because they are often a prerequisite to them, and the idea of a unique perfect match or soul-mate is a statistical impossibility," he reflects in a Guardian article.

On a New York Times thinkpiece entitled "In Defense of Tinder," Eli J. Finkel of Northwestern University concludes that Tinder is superficial by nature since it relies on swiping rather than profile matching and compatibility algorithms. "But this approach is at least honest and avoids the errors committed by more traditional approaches to online dating," says Finkel, who has previously critiqued Match.com-style dating site engines.

"Love at Second Sight," a recent Scientific Reports article by Jessica Taubert, Erik Van der Burg and David Alais, examines how one's perception of facial attractiveness can be influenced by the face that came before it. The authors presented female college students with 60 images of male faces and asked them to rate each one as attractive or unattractive. The study's participants viewed each face for only 300 milliseconds before making their choice.

"Online dating sites and apps inspired the framing of the task," says Taubert of the University of Sydney on that institution's news blog. The researchers learned that a man's facial attractiveness rating was improved by being viewed immediately following a highly attractive man's face.

"Previous studies have shown contrast effects, in which people in photographs look uglier when viewed next to portraits of attractive strangers," notes Scientific American. But the new study shows that appraisals can be done so quickly that faces begin to blend together. The conclusion is clear: swipe too fast on Tinder, and you might mistake a troll for a ten.