Studies surrounding relationships and marriage really began in the 1970s because people were worried about the divorce rate and what affects that could have on their children. Brit.Co explains that the long lasting couples (those who didn't divorce) all shared two things in common.

Kindness is one of them. Being kind to someone will always be a positive motivator. In a loving relationship, that could mean doing the dishes after dinner, or running a hot bath or shower for your partner after they've had a long day. It's not hard to be kind, but after years together with someone, the little things that you think about in the beginning probably get forgotten. Try not to let that happen.

Generosity is the other. If there is one last pancake on the stack in the middle of the table at breakfast, think about offering it to your partner instead of taking it yourself. I've never heard any one say that their partner was ever too generous, and maybe that could be something you could strive for.

All relationships are not created equal, but if all it takes to find success in love is to be kind and generous, then I think we can all find ourselves wildly successful.

(via Brit.Co)