While Watson didn't use those exact words, his theories strongly emphasized the influence of the environment on human behavior. He believed that all behavior, even complex emotions and thoughts, could be explained by learned responses to environmental stimuli. This idea is often summarized in the phrase "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." This statement clearly highlights Watson's belief in the overwhelming influence of the environment.
It's important to note that, while Watson's ideas were influential, they have been challenged and debated extensively. Many contemporary psychologists believe that while the environment plays a significant role, it is not the only factor shaping human behavior. Genetics, personal experiences, and individual choices also contribute to who we become.
Therefore, while John B. Watson is the most closely associated with this concept, it's more accurate to say that the idea that a person is a product of his environment is a complex one with a long history of philosophical and scientific discussion.