What did Ed say contributes to the longevity of his marriage with Janet?

The longevity of Ed's marriage with Janet is attributed to their ability to disagree constructively. This indicates that they have developed a skill set that allows them to handle conflicts in a healthy manner. Learning how to disagree means that they respect each other's viewpoints, engage in discussions that may challenge their opinions, and ultimately find resolutions that work for both partners.

This skill is crucial in any relationship because it fosters open communication and prevents the buildup of resentment. Disagreements are a natural part of any marriage, and how a couple navigates these disagreements can significantly impact their relationship's strength and resilience over time. Thus, Ed highlights this ability as a key factor in maintaining their harmonious and enduring partnership.