Are there many who do?
Many don't. I found out that my professor that I idolized is as normal as anyone and I love him even more! Many years ago he told everyone to not let their kids watch The Simpsons. There was a faculty and student party at a swanky home owned by one of the profs and her husband, a doctor. I mention the professions because they had a dual income and one child. Amazing place, they retained a professional chef. Anyway, we were there and the god professor's wife and he decided to go. (They were both psychologists, by the by.) He went to get their daughter who was four and she came up stairs yelling at her daddy that she did not want to go. Had this happened with anyone else it wouldn't have garnered so much attention, but this was a chance to see this man in action in real life. He didn't realize that we were all watching and he was bickering with her as parents do, trying to reason with a four year old-- he'd told me, "Do not try to reason with a two to four year old. You will lose every time!" He told his daughter, "Now you get your coat on and we are going to leave now!"
She glared at him, "Daddy, you're a dumb butthead."
He looked at his wife, "I'm getting the car, you get her ready!"
We laughed about that for months! Not at him-- he was so normal. Those two would split up and I'd hear from TAs who were close to both that they had the same problems as anyone else on miscommunication.
Later I would have a condo and see my college adviser (he was in the counseling department) occasionally visit my neighbor who was also a psychologist-- turns out they were divorced. I asked how on Earth they had marriage problems and couldn't get along. Same stuff-- miscommunication, bad listening skills, poor word choice. They got along great later. What shocked me was that I liked both of them but he told me that we need time to mature and grow and that kids strain marriages as does work and professional jealousies. She told me that then at work he was her greatest ally and that they supported each other in interdepartmental goings on.
Psychology will not make us better people.
I have tried applying my psych skills to my marriage and my husband gets irritated with me. My husband is a mathman and he says, "I didn't marry Carl Jung! Knock that sh-- off!" Too funny.