"So if you pick the right person and you know now to sustain some of the joy, I think you can create a long-term attachment that is full also of periods of romantic love. We all want to sustain a long-term happy partnership and psychologists will give you a long list of smart ways to sustain it. But I’d like to say what the brain can add. I studied the brain and the first thing that you want to do is sustain the three basic brain systems for mating and reproduction. Sex drive — have sex with the partner; have sex regularly with the partner. If you don’t have time, schedule the time to have sex with the partner because when you have sex with a partner, you’re driving up the testosterone system so you’re going to want to have more sex. But you also have all the cuddling, which is going to drive up the oxytocin system and give you feelings of attachment and having sex with the person, any kind of stimulation of the genitals drives up the dopamine system and can sustain feelings of romantic love. So basically having — and of course there can be good jokes about it and relaxation about it that is good for the body and the mind. So have sex with a person and sustain that brain system of the sex drive. To sustain feelings of intense romantic love, do novel things together. Novelty drives up the dopamine system and can sustain feelings of romantic love.
And this isn’t just in the bedroom. Just go to a different restaurant on Friday night. Take your bicycle instead of a car. Read to each other in bed. Sit together on the couch and have a discussion about something new. Read new books together. Novelty, novelty, novelty sustains feelings of intense romantic love. You also want to sustain feelings of deep attachment and to do that you have to just stay in touch. Learn to sleep in the person’s arms, at least start that way. Cuddle after dinner. Walk arm in arm down the street. Hold hands together. Put your foot on top of his foot or her foot while you’re having dinner, gently of course. But stay in touch. That drives up the oxytocin system and can give you feelings of deep attachment to the partner. So you want to sustain all three of those brain systems — sex drive, feelings of romantic love, and feelings of deep attachment.
But we’ve also found out what’s going on in the brain in long-term, happy partners. We did a study, a brain-scanning study of people who were married an average of 21 years. And those people who are married an average of 21 years who are still madly in love with their partner showed activity in three brain regions. A brain region linked with empathy, a brain region linked with controlling your own emotions, and a brain region linked with what we call positive illusions. The simple ability, but sometimes hard, to overlook what you don’t like about somebody and then focus on what you do. So last, but not least we’ve now known that if you say several nice things to your partner every day — I would suggest five but if you can only pull off two or three, whatever, saying nice things to your partner. That actually reduces their cholesterol, reduces their cortisol, which is the stress hormone, and boost their immune system. But it also boosts yours. So what the brain says about a happy, long-term partnership is overlook what you don’t like and focus on what you do. Express empathy for the partner. Control your own emotions. Have sex with the partner. Do novel things together. Stay in touch and say several nice things every day and you will — your brain will help you sustain a long-term deep attachment. We’re built to love." - Biological Anthropologist Helen Fisher via The Big Think