>>13000413It probably has to do with the correlation between waiting untill marriage and generally more traditional values. A person with more traditional values is probably less likely to resent their spouse or think of their marriage as holding them back. Same reason why arranged marriages work out as well or better than chosen marriages. Having a successful relationship is not about finding a person who is perfect for you, it is about compromise.
It addition to that, there probably is a biological element to it. Having sex pair-bonds you (to a greater or lower degree depending on some variables). If you have sex with a bunch of people, your ability to pair bond is diminished.
