A comprehensive analysis by researchers from the University of Colorado looked at more than 130 traits of millions of couples, which will definitely make you think about your relationship. The research actually challenges the old belief that differences are the trigger for a romantic relationship.

In 82 to 89 percent of traits, partners in long-term relationships showed striking similarities – from political leanings to lifestyle choices. On the other hand, only 3 percent of the traits showed some tendency to combine the opposites, reports "Healthy".

Political and religious beliefs

Study first author Tanya Horwitz says it's no shock that shared beliefs about politics and religion are one of the biggest indicators that a relationship can go far.

Education levels and IQ

Your level of education dictates your need for intellectual stimulation. Individuals in the US are increasingly finding partners with similar education. Although it seems counterintuitive, this pattern can potentially reinforce socio-economic disparities in the long run.

Height

Does height really matter? Well, as for the height, it could be. According to Horwitz, if shorter individuals primarily choose mates of similar height and taller people do the same, the next generation could see more pronounced differences in height. This model can be applied to a variety of inherited traits, from medical predispositions to quirky personalities.

Attitudes towards certain substances

Your attitude toward substances like alcohol and tobacco can significantly affect your romantic choices. The study revealed a clear pattern that heavy smokers, committed drinkers, or those who are completely abstinent often socialize with those who share their habits.

Year of birth

It may seem self-explanatory, but your birth year stands out as a beacon of compatibility. Couples often find partners who match their level of emotional maturity, perhaps reflecting shared generational experiences and values.

Other valuable discoveries

Research has shown that factors such as the number of past romantic partners or even early life experiences such as breastfeeding influence mate choice, albeit to a lesser extent. Certain personality traits, such as neuroticism, showed minimal but positive correlations. Interestingly, compatibility is not key when it comes to openness or reticence as character traits.

Although the evidence strongly suggests that similarities dominate romantic choices, there are exceptions. For example, certain traits such as sleep patterns (being a morning person vs. a night owl) and anxiety levels indicate potential opposites attract. However, the correlation was weak and requires further research.