Fern Britton believes her first marriage broke down after taking a test revealed she had a higher IQ than her husband.
The 64-year-old former This Morning presenter and author — who split from TV executive Clive Jones in 1998 after 10 years of marriage — revealed she passed the test to become a member of High IQ Society Mensa, but Jones failed.
Britton told the Walking The Dog with Emily Dean podcast: "He had this degree and I don’t. I secretly went off and did the Mensa.
“I lied, I said I was going somewhere else, and it took a day to do this test. I passed — and quite well too.
“Then he was furious so he did it because he’s got a huge brain. But he’s not a problem solver and he didn’t get it. So an immense rift opened.”
The TV presenter and Jones began a relationship when he was still married and began an affair.
They married in 1988 after he left his first wife for Britton and they have three grown up children — twins Jack and Harry and daughter Grace.
They began dating shortly after the breakdown of her marriage to Jones and married in 2000. They share a daughter, Winnie, who turns 20 in August.
Britton – who also competed in Strictly Come Dancing in 2012 – announced on Twitter that they were separating in January 2020.
She has since said: "We had a wonderful time. We were the best of friends. And I miss that friendship.
"But there comes a point when the children are substantially off your hands and you look at each other and wonder where you’re going to go from here."
And the successful novelist — who published her first book in 2011 — said she is now learning to make herself happy.
Britton said: "I’m not lonely but I’m in this transition period where I’m working out what’s next for me. My approach has always been, head down, keep going, and for the first time in my life, I’m thinking, ‘Hang on, where shall I go now?’ – and that’s quite nice. Suddenly, the world is my oyster.”
Watch: Fern Britton talks family secrets with Kate Thornton