NEW YORK (Reuters Life!) – Couples who get to know each other before being intimate have a better chance of having a lasting relationship, but in some cases even a casual fling can lead to true love, according to a new research.

Most of the 56 percent of 642 adults questioned in the study who said they had waited until they got serious before they had sex reported having a high quality relationship.

The number was higher than for the 27 percent of people who had sex while dating casually and the 17 percent who were intimate while in a non-romantic relationship. "There's something about the characteristics of people who wait before sex that is linked to higher-quality relationships," said sociology professor Anthony Paik of the University of Iowa.

Paik, who reported the findings in the journal Social Science Research, said the research suggests that the courtship process acts as a screening mechanism.

"The debate is 'why can't we have sex now?' The expectation is that sex should occur very quickly. But doing so, you're losing out on some information that might be useful," he explained in an interview. It's almost an economic equation, he added.

"On average, the more costly the process leading into the relationship, the more likely it is to work. That's what the data would suggest."

But Paik said the findings did not show that an early sexual relationship had a direct negative impact on relationships.

When he filtered out people who said they had frequent non-romantic or casual dating sexual relationships he found that the gap in relationship quality between serious and nonserious contexts of sexual activity disappeared. "It means it's possible for two strangers to lock eyes in a bar, and go home together, and actually end up in a long-term relationship," Paik said

The reason more people who have sex in a non-romantic relationships report lower quality relationships has more to do with who we are than when we chose to have sex, said Paik.

Certain people are simply prone to finding relationships less rewarding, and they are more likely to have sex in casual relationships, he added.