Robin Hanson reports that success in marriage is quite uncorrelated with the match between your personality traits and your partner’s. Your traits matter (it pays to be happy, for example) and so do your partner’s, but the combination makes no difference. ...The point is that correlation does not imply causation. A lot of social science research mixes up cause and effect, and draws faulty conclusions.
NO!!!! That’s not the right conclusion at all, and it’s worth understanding why not. Suppose we lived in a world where personality matches had a huge effect on the success of marriages. In that world, why would two people with clashing personalities ever choose to marry? Presumably because there’s some special value in the match — like, say, an extraordinary mutual attraction — that overrides the personality clash. ...
For example, taking aspirin is correlated with having headaches. But that fact alone does not tell you whether the headaches are causing the aspirin, or the aspirin is causing the headaches.
A reader adds:
An example from Dr Phil where he explains to a couple that open marriages don’t work because in a professional setting he often sees couples in an open marriage with marriage troubles. I rolled my eyes when I heard that.I mention this because psychologists and family court employees often have bizarre ideas about child rearing and parental disputes. They have years of experiences noticing certain types of complaints in their practice and in court papers, but they are very confused about what is causing the problems, and what is curing them. And they don't see cases where both parents are doing well, so they have no idea what works and what doesn't.
For example, a court psychologist might say that parents should never talk to their kids about money. If you ask why, he might say that in his many years of experience, he has seen many complaints from bitter ex-spouses about money discussions. So he infers that talking about money is bad.
Can you see the flaw in this logic? Yes, if you do not talk about money then there should be no complaint about how you talk about money. That is true in the same sense that if you do not go to the beach, then you will not complain about sand in your toes. If you don't take the bus, then you won't complain about the bus. It is the same reasoning. No sensible person would take advice from anyone who reasons that way. You should not rear your kids on advice from court personnel any more than you should choose a mate based on the above sloppy research on happy marriages.