Ken and Goldie Flanders celebrated their 60-year wedding anniversary in December.

Ken Flanders is a big believer in love at first sight. It happened to him in 1946 when, while pitching a ballgame in Highland, he caught a glimpse of his future wife in the stands.

“I actually caught more than a glimpse,” Ken, 78, Lawrence, recalls with a chuckle. “I saw her up in the bleachers and after the game, I thought I’m going to find out who that little gal is. I got up there and she was gone. Nobody there knew her. She was just visiting in town.”

In fact, she was visiting on the arm of another suitor.

“This other boy took me to the ballpark,” says Goldie Flanders, 78, “but when (Ken) saw me, he says he knew that he was going to marry me.”

“I never had that feeling before and haven’t had it since. I guess I’d better not have had it since,” Ken says, laughing.

Helen Fisher, biological anthropologist, scientific adviser to Chemistry.com and author of “Why We Love: The Nature and Chemistry of Romantic Love,” says Ken experienced a profound chemical reaction in his brain that summer day.

“There are three brain systems,” she explains. “One is for the sex drive, second is for romantic love and third is the system for attachment.”

Fisher says the sex drive is fueled by testosterone in both men and women.

“The sex drive evolved to get us out there, looking for anything at all. The feeling of romantic love is associated with the dopamine system,” she says. “So, when you take a look at your sweetheart, a tiny part of your brain called the ventral tegmental area, or VTA, produces dopamine and sprays this chemical to many brain regions. It’s something we can see clearly on MRI scans.”

Dopamine is a natural stimulant, the brain chemical associated with focused attention, craving and elation.

“It also has to do with addiction and motivation,” Fisher adds, “and, in this case, motivation to win life’s greatest prize, the right mate and partner.”

Dennis Dailey, professor emeritus of social welfare at Kansas University and clinical sex and marital therapist, downplays the role of dopamine.

“I don’t think there’s a question that it’s a very powerful hormone,” he says. “But it’s really more about how two people work at making a relationship. When you think about chemistry at that level, the endocrinological or hormonal component is fairly minor.”

So what brings men and women to get together, if it’s not our biology?

“I think things like attraction, need, desire for intimacy and connectedness, the importance of embrace and touch,” Dailey says. “I don’t think there’s any question that part of what drives us is arousal, but it’s so much more complex and complicated than that.”

Flanders, a retired pharmacist, believes there was some kind of weird science at play that afternoon on the mound.

“I think chemistry kicked in that day,” he admits.

Ken was motivated to win the elusive Goldie but didn’t know where, or even who, she was. Fortunately, fate intervened and she moved to town the very next year, enrolling in Ken’s high school. A whirlwind courtship ensued.

“We never dated anyone else after our first date,” Goldie says. “We went together for about two years and got married the December after we graduated. We were 18.”

The couple celebrated their 60-year anniversary last year.

Over the years, Goldie and Ken’s brains likely started replacing large amounts of dopamine with other powerful chemicals, Fisher says.

“The attachment system — another form of love — has been associated with oxytocin and vasopressin in the brain,” she says. “These are chemicals that can make you feel calm and secure, and seem to be associated with nurturing, trust and long-term love. As dopamine diminishes, oxytocin starts to increase.”

Some people, she says, feed on the rush provided by romantic love, and when the dopamine well runs dry, they’ll often lose interest in their partner.

“There are just some people who need thrills,” Fisher notes. “But a lot of people who need thrills stay with their partner by reading widely, traveling with their partner and so forth. There’s more than one way to kick that dopamine in without a divorce. Novel experiences help to do that.”

“I’ve never been bored,” Goldie claims, admitting that living in several cities throughout the U.S. and Canada, and raising two boys and a daughter, helped keep monotony at bay.

“Living all over like we did, you know, we made different friends in different places, and we’ve taken those with us,” she says.

Dailey says that couples who go the long haul tend to share a common denominator, and it’s not elevated oxytocin or dopamine levels.

“Emotional intimacy is required in a successful relationship,” argues Dailey, “particularly a long-term relationship, to deal with all of the issues that are going to arise when you have two very interesting and different people in a relationship, and you try to sustain it for 50 years.”

The Flanders were tested in that way when tragedy struck not long after their wedding day.

“Early on, we lost a boy,” Ken reveals. “He was 4 months old, our first child. I think it was probably that — with our faith — that kind of solidified our marriage. It was either, you accept it and go on, or we’ll part and try this with somebody else.”

Goldie agrees. “I think we felt we had to pick up our lives and go on. We couldn’t wallow in our grief. It made us both so much stronger. We were so young when we got married, and then to go through all that. We grew up in a hurry.”