John B. Watson, one of my “Big 3” in regards to behaviorism in psychology.
John B. Watson (January 9, 1878 – September 25, 1958) was an American psychologist, influenced by Ivan Pavlov who established the psychological school of behaviorism. Through his behaviorist approach, Watson conducted research on animal behavior and child rearing. He was considered an expert in child rearing, influencing the writings of Dr. Benjamin Spock. In 1946, Spock published his book The Common Sense Book of Baby and Child Care, which became a bestseller. Its message to mothers is that “you know more than you think you do.” By 1998 it had sold more than 50 million copies. It has been translated into 39 languages.
Watson’s – The 12 Infants Quotation
Give me a dozen healthy infants, well-formed, and my own specified world to bring them up in and I’ll guarantee to take any one at random and train him to become any type of specialist I might select – doctor, lawyer, artist, merchant-chief and, yes, even beggar-man and thief, regardless of his talents, penchants, tendencies, abilities, vocations, and race of his ancestors. I am going beyond my facts and I admit it, but so have the advocates of the contrary and they have been doing it for many thousands of years. [p. 82] 
The 20th century marked the formation of qualitative distinctions between children and adults. Watson wrote the book Psychological Care of Infant and Child in 1928, with help from his mistress, turned wife, Rosalie Rayner. Critics then determined that the ideas mainly stemmed from Watson’s beliefs because Rosalie later entitled a self-penned article I am a Mother of Behaviorist Sons. In the book, Watson explained that behaviorists were starting to believe psychological care and analysis was required for infants and children. All of Watson’s exclamations were due to his belief that children should be treated as a young adult. In his book, he warns against the inevitable dangers of a mother providing too much love and affection. Watson explains that love, along with everything else as the behaviorist saw the world, is conditioned. Watson supports his warnings by mentioning invalidism, saying that society does not overly comfort children as they become young adults in the real world, so parents should not set up these unrealistic expectations. Writer Suzanne Houk, Psychological Care of Infant and Child: A Reflection of its Author and his Times, critiques Watson’s views, analyzing his hope for a businesslike and casual relationship between a mother and her child. Watson disapproved of thumb sucking, masturbation, homosexuality, and encouraged parents to be honest with their children about sex. Watson’s reasoning for this was that, “all of the weaknesses, reserves, fears, cautions, and inferiorities of our parents are stamped into us with sledge hammer blows”. Watson inferred that emotional disabilities were a result of personal treatment, not inherited.