Did you read your article? It goes pretty far to say that while this study makes a few suggestions, theyre hardly conclusive.
Humans beings are too complex for any one factor, especially something as unimportant as sexual history, to be an accurate indicator of how succesful their relationship will be.
All excerpts from
your article.
"In other words, correlation should never be confused with causation."
“We cannot make any conclusions about cause-and-effect,” says
Justin Lehmiller, PhD, sex educator and researcher at Purdue University, adding, “Could it be that multiple premarital partners impacts marital happiness? Maybe. But it could also be that people who have more partners have different personalities or different attitudes toward marriage or relationships.”
"But isn’t that another way to say they might be more aware of a
bad relationship? Isn’t that a good thing?"
"Indeed, while the data presented in The Marriage Project’s 418-person study is legitimate, experts say that the conclusions drawn from it — especially those which cast judgement on one’s sexual history and incite sentiments of slut-shaming — may not be entirely accurate."
"Researchers in this field, who were not involved with this particular study, told The Huffington Post that these findings should be taken with a grain of salt."