Drs. Astro and Danielle Teller know better than most that finding the right partner in life doesn't always happen the first time around.

Through their own divorces they learned how widely held cultural assumptions and misinformation that nobody thinks to question-what they refer to as "sacred cows"-create unnecessary heartache for people who are already suffering through a terrible time.

Do you think, for example, that the divorce rate in the United States is rising? Or that children are harmed by divorce? Most people do, but it turns out that neither of these...