The Common Sense Book of Baby and Child Care, published in 1946, sold over 50 million copies by the time of Spock’s death in 1998. The book has also been translated into 39 languages.

Prior to Spock’s book, child care experts recommended rigid schedules for the feeding and toileting of infants and cautioned parents not to show excessive affection for their children. In contrast, Spock recommended flexibility in child-rearing and the recognition that each child was an individual.

Influenced by his own psychoanalytic training, Spock emphasized that childhood behavior and motivation was variable at each stage of development, and parents should make their own decisions, rather than follow the authoritative advice of presumed experts regarding how to raise their children. Above all, he urged parents to have confidence in their abilities and trust their own common sense.