For five years, 1954 to 1959, at the National Institute of Mental Health, psychiatrist Murray Bowen conducted a most unusual research project, focused on schizophrenia. Adult patients and their parents were hospitalized together for observation and treatment. The intensity of the emotional process in these families—the sensitivities, reactivity, and the profound influence of family members on one another’s functioning–came into view. Like a powerful undercurrent, this emotional system was guiding family interaction but was largely out of the awareness of the members. It is aptly called “the hidden life of families.”