Whether a relationship is good or not depends mainly on how you feel within it, not on your partner’s attributes

There is no monetary cost, nor does it require much time. The real challenge lies in shifting your perspective: put aside your checklist of ideal partner traits and instead focus on how you interact with each other.

A machine-learning analysis of 29 labs and 43 longitudinal paired datasets — longitudinal means following the same couples over time — found that the strongest predictors of relationship quality all came from how each person felt about the relationship: sensed commitment from the other, appreciation, sexual satisfaction, sensing the other’s satisfaction, and conflict. Among person-level items the strongest were life satisfaction, negative emotion, depression, avoidant attachment, and anxious attachment. These relationship items explained at most 45% of the variance at the start of the survey. Variance here is the difference in relationship quality between couples; 45% is the part those items can account for. By the end of the study they explained at most 18%. And the predictive power of “items you report yourself” was two to four times that of “items your partner reports.” Adding individual differences and the partner’s reports on top of your own relationship feelings added no further predictive power. Whether the relationship got better or worse during the study was largely unpredictable from any set of self-report measures; the original wording is “largely unpredictable from any combination of self-report variables.”

Joel S, Eastwick PW, Allison CJ, et al. (2020). Machine learning uncovers the most robust self-report predictors of relationship quality across 43 longitudinal couples studies. Proceedings of the National Academy of Sciences, 117(32), 19061-19071. https://doi.org/10.1073/pnas.1917036117

To judge whether this relationship is good right now, asking how you feel is more accurate than checking the other person’s attribute list, but do not expect to predict how it will go later. The account that links relationship quality to physical health is in item 17 of this section (treat relationship quality as a health account).