Catharine MacKinnon
Masson is married to Leila Masson, a German pediatrician. They have two sons. He also has a daughter by a previous marriage with Therese Claire Masson. In the early 1990s, Masson had been engaged to University of Michigan feminist legal scholar Catharine MacKinnon, who wrote the preface to his "A Dark Science: Women, Sexuality, and Psychiatry in the Nineteenth Century".