Lester W. Sontag, Antioch College's (Yellow Springs, Ohio) physician, was appointed as the first Director for the Fels Longitudinal Study in 1929. The first participants were enrolled prenatally by their parents, and the first examinations began in 1930. Lester Sontag remained active in the study, developing and nurturing it until his retirement in 1970.
In 1940s, Lester Sontag, M.D., was the first scientist who discovered that the mother's heartbeat affects the heartbeat of the unborn child in the womb in many ways. Sontag found that war had transformed what in peacetime were occasional fears of danger into a daily reality for hundreds of thousands of pregnant women with soldier husbands. Sontag theorized that these fears served to heighten a child's biological susceptibility to emotional distress while still in the womb. He named this phenomenon "somatopsychics" and defined it as the way "basic physiological processes affect the personality structure, perception and performance of an individual." The person's body machinery predisposes him toward such psychological disorders as anxiety or depression and there are neurohormonal loops that link the mother to unborn child. Sontag's ideas are best described in his "Implications of Fetal Behavior and Environment for Adult Personalities," Annals of the New York Academy of Sciences 134 (1965)
From the guide to the Lester W. Sontag Papers, 1933-1969, (History of Medicine Division. National Library of Medicine)