The day that Gov. John Hickenlooper announced his engagement to Robin Pringle, radio talk-show host Jon Caldara turned it into a hot topic on his KHOW radio show.

"Congratulations to

our governor, I wish him all the best, and come on! He is 63 ... and he's hooking up with Robin Pringle, who is 37. What is that? About 25 years difference?"

The couple, who are expected to wed this weekend, are hardly an anomaly. But the topic has long fascinated the American public, from water-cooler conversations to celebrity magazines.

(Photos from Getty Images)

Even academics are part of the conversation, producing such research papers as "May-December Paradoxes: An Exploration of Age-Gap Relationships in Western Society" from Purdue University, which explores the mystery of why "heterosexual age-gaps only seem to be socially acceptable when the older partner is a man."

Among relationship experts in Denver, opinions are abundant.

"I think this circles a lot around the idea we have of staying youthful," said Beth Hooper, founder of Elite Matchmaking Services in Denver. "I see a lot of older men who want to stay vibrant by being with a younger woman. I think in male society they think, 'Wow, you must be really amazing if you can get a woman who is 15 or 20 years younger.' "


Most of her male clients are between 40 and 70, and "every single one of those men would be perfectly happy to marry someone 20 years younger," she said.

"For women, I see the reverse. They're not interested in something with a large age gap. I might say to a woman who's 50, I have got a fantastic man for you, he's 74, and she'll say, Oh my God, health issues."

Jonathan Bricklin and Susan Sarandon attend the Susan Sarandon Kicks Off SPiN New York’s East Hampton Pop-Up At c/o The Maidstone Hotel on June 30,
Jonathan Bricklin and Susan Sarandon attend the Susan Sarandon Kicks Off SPiN New York's East Hampton Pop-Up At c/o The Maidstone Hotel on June 30, 2013 in East Hampton City.

Experts point out that the same age gap — say 25 years — is quite different between earlier years, like 30 and 50, and later in life, such as 65 and 80. That same gap seems to widen as people age and energy or activity begins to diminish.

But at younger ages, the age gap is often perceived to have certain benefits.

"For the older person there is chemistry and sexual excitement," said Howard Markman, co-author of "Fighting for Your Marriage" and director of the Center for Marital and Family Studies at the University of Denver. "Evolutionary pressure points us in that direction. People want to be with the most beautiful person they can be with, both men and women."

As for the younger partner, "We're all attracted to wealth and power," he said. "And you get financial security a lot earlier."

This perception, however, is challenged by a study co-authored by Hani Mansour, an assistant professor of economics at the University of Colorado Denver, published in 2014 in the "Review of Economics and Statistics."

The goal was to understand what kinds of people enter into age-gap relationships — whether the reality is different from the Hollywood scene where financially successful older male actors often marry women a few decades younger.

"We were surprised to find that when you look at the entire population, things look very different, especially if you look at age gaps in first marriages," said Mansour.

Researchers found that men and women in age-gap marriages of about 10 years have lower annual earnings, lower-wage occupations, and lower cognitive skills.

"We think it has to do with choices people make when they're young," said Mansour.

While research on age gap relationships is limited, with results that are sometimes contradictory, people who work daily in the field agree on the challenges such couples face — including social disapproval and stereotyping, which is usually worse for women.

Actors Amber Heard (L) and Johnny Depp attend The Art of Elysium 2016 HEAVEN Gala presented by Vivienne Westwood & Andreas Kronthaler at 3LABS on January
Actors Amber Heard (L) and Johnny Depp attend The Art of Elysium 2016 HEAVEN Gala presented by Vivienne Westwood & Andreas Kronthaler at 3LABS on January 9, 2016 in Culver City, California. (Jason Merritt, Getty Images North America)

"If a woman is 10 to 15 years younger, no matter when she meets this guy, she'll be seen as a homewrecker, a trophy wife or a gold digger — even if she meets him five years after his divorce," said Mary T. Kelly, a Boulder psychotherapist who specializes in stepfamilies. "Women get a lot of judgment they're not really expecting."

And when the age gap is very large — 15 or more years — there's the challenge of intergenerational relationships — Boomers with GenXers or Millennials. People from different age groups grow up in different cultures with their own music and cultural touchstones. Their social circles are different, and so are their life stages.

"The major issue is that you're going to have more differences when you have a substantial age gap," said Markman. "And whenever there are more differences there are more challenges to handle, and when there are more challenges, there are more disagreements and conflicts, so there's more risk of divorce. Couples aren't very good at handling negative emotions around disagreement."

There can be disagreements over starting a new family, with issues ranging from infertility to reverse vasectomies.

"They cause a lot of resentment and jealousy among the first family because men tend to devote more time to the second family," said Kelly.

And sometimes women in their 20s and 30s don't want kids when they marry older men with families of their own, so both spouses are on the same page — until she changes her mind.

"Once they're married and see their husbands involved with their children, they want to have kids of their own," said Kelly. "It can be heartbreaking, and it can become a litmus test, if you really love me, you'll give me a baby."

Despite the downsides of age-gap relationships, experts say there's also a silver lining.

"Age-gap partners are often more satisfied and committed to one another than partners who are more similar in age," said the Purdue University study. "Thus, it is clear that despite the potential downsides, many of these relationships do in fact stand the test of time."

Hope Rike, director of the dating service It's Just Lunch Denver, has been matchmaking for a decade.

"Each client has a personal preference about the age range they're open to," she said. "We always encourage them to be as open as possible when looking, so it's not just about dating a particular age."

Because, in the end, there's one thing that truly matters.

"It's more about having good communication, age gap or not," she said. "It's about two different people with two different experiences working together to be a partnership."

Colleen O'Connor: 303-954-1083, This email address is being protected from spambots. You need JavaScript enabled to view it. or @coconnordp

Some notable age gap relationships

Rolling Stones guitarist Ronnie Wood married Sally Humphreys in 2012. With a 31-year age gap, they are expecting twins in 2016.

Musician Billy Joel married his girlfriend Alexis Roderick last year. They have a 33-year age gap.

Michael Douglas and Catherine Zeta-Jones, married for 15 years, have a 25-year gap.

Hugh Hefner, founder of Playboy Enterprises, has a 60-year age gap in his marriage to Crystal Hefner.

Publisher Rupert Murdoch and Wendi Deng had a 44-year age gap, divorcing in 2014 after a 14-year marriage. This week he announced his engagement to former model Jerry Hall, 25 years younger.

Susan Sarandon has had a five-year romance with Jonathan Bricklin, with a 31-year age gap.

Woody Allen and Soon-Yi Previn have a 34-year age gap, and have been married since 1997.

Johnny Depp recently married Amber Heard, with an age gap of 23 years.

Warren Beatty and Annette Benning have a 21-year age gap.

Harrison Ford and Calista Flockhart, married in 2010, are 23 years apart.