We’ve all heard the line about opposites attracting, and we all know couples who are as different from each other as night and day. You know the scenario – she’s a librarian, he’s a Harley-riding tattoo artist; he likes to “veg” in front of the TV every night, she likes to go dancing three nights a week; she’s well-educated, he’s a high-school dropout.

While passion may fuel short-term romance between polar opposites, if you’re looking for a life mate, you’ll have more success with someone whose lifestyle and aspirations more closely match your own. Don’t get me wrong – I’ve seen happy couples that you would never have guessed would be happy together who seem like total opposites, but their differences are typically surface differences: he’s tall, she’s short.  Other differences can work, but it takes work, patience, and understanding – particularly if you’re talking major cultural or religious differences.

There is something, though, about having very similar core values that makes a relationship successful and strong. Couples who tend to have the most long-term success share the same set of core values. If they are not of the same religion, they have the same religious or spiritual core that includes a healthy respect for others’ philosophies and a willingness to allow their children to be raised with both. Long-term success is also more easily sustained when the two people have a similar level of intelligence or education. That doesn’t mean PhDs should only date PhDs…it means that there should be an intellectual connection in which both parties feel fairly equal.

Other areas where similar core values seem to be important are physical activity level, finances, and the desire for children. Couples are more successful if both of them like to get out and go dancing three times a week than if half of the couple wants to go while the other half would prefer to watch TV every night. A shared passion for some activity (rock climbing, charity work) can also bind people together more closely. While two people don’t have to come from the same financial background to have a successful relationship, their attitude about money, saving and spending, and earning habits should be similar. Kids – or not wanting them – can be a major deal breaker. There is no right or wrong, but if you’re not both on the same page about wanting to raise a family, you will most likely face some major struggles.

Opposites attract … it’s why the “good” girl always wants the “bad” boy in every 80’s movie ever made. For lasting and fulfilling love, try to find someone with whom you have more in common than a passionate spark that will fizzle fast.