Economists have a history of studying many aspects of dating and relationships. While this might seem surprising to a non-economist, from research on what people find most important in their dream partners to whether online dating can predict real chemistry, economists have explored a plethora of topics in this area.
This article asks whether the personalities of you and your partner can predict partnership longevity; and if yes, what the “optimal” personality matches are.
Rammstedt et al. (2013) utilize a dataset that followed 5,000 German couples for five years, reassessing their personality and asking about their relationship status each year.
First, the authors asked whether personality affects partnership longevity, or the duration of the relationship in plain English. For this, they compared the personality congruence (i.e. similarity in personality) of couples who seperated, and couples who did not seperate sometime during the 5-year study.
The results quite interestingly show no difference in personality congruence between stable and seperated couples in the first year of the study for 2 out of the 5 traits. Namely, it doesn’t seem to matter whether your partner is much more (or less) extroverted, or agreeable than you. To a certain extent it seems to matter that both of you be conscientious but this is still not the deal breaker in most cases, as the difference between stable and seperated couples in this trait is not statistically significant from zero.
What seems to be the only statistically significant difference between stable and seperated couples is that stable couples are much more alike when it comes to openness to experience. Stable couples had on average a 0.29 congruence on this trait versus only 0.11 for seperated couples. This is significant at the 5% level.
Moreover, congruence in one trait, neuroticism, seems to be a bad thing. Neurotic individuals are very skeptical, negative and pessimistic. If both individuals are neurotic, this seems to sort of poision the relationship, as congruence in neuroticism is higher for seperated couples. Neurotic relationships, however, are not as doomed as one might think, as the difference is not statistically significant here, either. It seems thus that the most important trait to concentrate on is openness.
Secondly, the authors looked at how personality congruence varied over time. They found that for stable couples, there was no change at all. Stable couples, as their name suggests, stay stable in their congruence over the five-year period of the study. It appears thus that couples are not growing apart or together, at least in terms of their peronality, over the course of a relationship. (Important side note: the authors controlled for age, education, and marriage duration.)
Interestingly, however, seperated couples grow even farther apart. That is, the difference between their congruence in year 1 and year 5 is positive. It is only significant for openness though. This might mean that people who seperated overcompensate for something they couldn’t have for a long time. Or that finally they can be themselves. Or perhaps a mixture of the two.
Thirdly, let me just talk about the congruence figures in general. What Rammstedt et al. find is that in their sample congruence is largest in coscientousness (0.31), openness (0.29), and agreeableness (0.25); and that there is little to no congruence in neuroticism (0.14), and especially extraversion (0.07). (The numbers in parentheses are for stable couples.) Now, as we saw above these congruence numbers tend to be similar (or even the same) for stable and seperated couples, with the most notable exception of openness where seperated couples only have 0.11.
What this shows is that two people are more likely to actually start a relationship if they’re more similar in conscientousness, agreeableness, and to a lesser extent neuroticism and openness. Later on, however, differences especially in openness can create tensions and break up the couple. So it appears openness is far from being the most important determinant of whether you enter into a relationship with someone, yet it becomes the most important trait in predicting whether your relationship can last.
So the interesting thing is that it seems that people already get matched by conscientiousness, and agreeableness while they’re just dating. But differences in openness don’t get noticed or paid much attention to at this stage for some reason. This is what can cause the end of a relationship later on.
Of course, everything in this study is true on average. So as always with statistics, there are exceptions, and one shouldn’t be discouraged by a study like this. If, however, you’re still on the dating market, you might want to make sure your future partner is about as open to new experiences as you, to maximize the probability of a successful relationship.