Central to Watson’s theory of behaviorism was the enormous influence of the environment. Human behavior, he argued, could be shaped through learning, conditioning, reinforcement, and life experience. Change the environment and experiences surrounding a person, and you could potentially change the person.

Nature, nurture, or both?

John Watson strictly adhered to the idea that it is indeed one’s surrounding environment that most directly impacts and shapes our lives, and that by changing our environment, we essentially change who we are and what we will become. In his 1924 book Behaviorism, he issued one of psychology’s most famous challenges:

“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…”

While completely unethical by today’s research ethics, think about what Watson was proposing in theory. If you were to give him a group of healthy infants and complete control over their environments, he believed he could largely determine what they would eventually become. Watson believed inner thoughts and emotions had far less impact on human development than the surrounding world around the individual, especially with respect to behaviors that are continually reinforced. These days, that sounds extreme.

Fast-forward to today, where we know far more about genetics than psychologists did during Watson’s era. We now know that children aren’t interchangeable blank slates. Temperament, intelligence, personality tendencies, physical abilities, genetic predispositions and other biological characteristics all contribute to development in varying degrees. Modern psychology generally doesn’t frame human development as nature versus nurture, but instead views nature and nurture as continually interacting.

Interestingly, even Watson himself later acknowledged that his famous statement exceeded what he could scientifically demonstrate, writing, “I am going beyond my facts and I admit it.” But before dismissing Watson entirely, consider a thought experiment. Imagine two children born with essentially identical biological potential. One grows up in a safe home filled with books, encouragement, affection and stability. The child attends prestigious schools, participates in activities, meets with inspiring teachers and coaches, develops friendships with achievement-oriented peers and grows up surrounded by adults who continually reinforce the expectation that effort will eventually produce opportunity.

Now place the other child in a dramatically different environment where there is instability at home, limited educational opportunity, few positive role models, unsafe surroundings and little hope and encouragement. Instead of opportunities continually appearing, obstacles continually do. Would we really expect these two children to arrive at adulthood unchanged by those dramatically different experiences?

It is also important to note that “environment” extends far beyond parenting. We are also influenced by teachers, coaches, and friends, as well as our neighborhood and school. Socioeconomic status impacts our development, as do the number of times we are praised and encouraged by others. In fact, sometimes it is just one teacher, coach, or friend who changes the direction of someone’s life.

While Watson himself admitted he may have over-estimated the influence of environment and surroundings, he did help us better understand that those factors do indeed have a great influence on human development. Watson pushed the environmental argument toward its extreme, but the other extreme (also false) would be to assume that it is biology only that is responsible for human development.

Final thoughts

Perhaps the most provocative part of John Watson’s argument isn’t whether he could actually turn any infant into a doctor, lawyer, artist, or thief, but what his claim forces us to consider about ourselves. How much credit — or blame — should we take for the people we eventually become? We like to think our personalities, values, interests, accomplishments, and even our failures belong uniquely to us. But imagine being born into a different family, attending different schools, receiving different encouragement, and encountering entirely different opportunities. Would you still be recognizably you? Watson may have pushed nurture much too far, but perhaps his greatest contribution was forcing us to confront an uncomfortable possibility: the line between who we are and what our environment made us may be far more difficult to draw than we’d like to believe.