to be fair, the reason isn't the cohabitation itself. the research was basically summarized as:
- some couples cohabitate too soon cuz they wanna save on living costs, not have a new stage of the relationship
- those same couples might not actually be right for each other but they close off their other options n have a harder time leaving, cuz of that shared lease n getting used to split expenses b
- some other couples r debating marriage but move in together as a trial period. allegedly, couples who feel the need to do a trial period r usually doing so cuz they aint certain. then since society expects ppl to get married after a certain # of living together, the couple who was on a trial period might end up getting married "just because" it's been enough living together, not cuz it's whats best.
so its the couples, not the shacking up. the higher divorce rate is cuz of the reasons why they cohabitated. im sure the couples that wld've lasted regardless do not divorce cuz they shacked up beforehand.