An Absurd Claim From Psychologists About Matching & Mismatching

An interesting claim has been made in the Journal of Personality and Social Psychology that finding a partner that will make you happy isn't so much about finding a well-matched person, but about being a happy person yourself and finding someone who is generally a happy person too. Although the claim is interesting, it is also absurd:

"Three very large, nationally representative samples of married couples were used to examine the relative importance of 3 types of personality effects on relationship and life satisfaction. … Using data sets from Australia (N = 5,278), the United Kingdom (N = 6,554), and Germany (N = 11,418) … Actor effects accounted for approximately 6% of the variance in relationship satisfaction and between 10% and 15% of the variance in life satisfaction. Partner effects (which were largest for Agreeableness, Conscientiousness, and Emotional Stability) accounted for between 1% and 3% of the variance in relationship satisfaction and between 1% and 2% of the variance in life satisfaction. Couple similarity consistently explained less than .5% of the variance in life and relationship satisfaction after controlling for actor and partner effects."

What makes it absurd is that there is an obvious error of reasoning here. In surveying only married couples there is a large and substantial omission of all those potential couples that never got together due to not being well matched and not having the kind of character qualities the study is considering. Consequently, then, this survey does not demonstrate that being well-matched is unimportant.

Suppose the psychologists are wrong and being well-matched really does matter - surveying only married couples is not going to confirm this because it omits all the instances (instances you'd find in a random survey) where potential marriages broke up because of mismatched personalities.

The other problem is that even among married couples there are going to be many who are (still) together not because of wonderfully matched personalities, but because of other mutually attracting forces such as physical attraction, religious commonality, children, money, or convenience that override personality mismatching. Furthermore, there are, doubtless, many mismatched couples who got together because of ticking biological clocks, fear of being single and concern about whether either of them will ever find someone to settle down with.

The upshot is, the results of the Journal of Personality and Social Psychology survey quoted above are perfectly consistent with a world in which ideal matching of personality isn't all that important, but they are also perfectly consistent with a world in which ideal matching of personality is very important, which means the survey isn't telling us what is being claimed.