In the early 1940s, a teacher at an immigrant school in Brooklyn gave a standard achievement test to a young Jewish boy who had recently joined her class after fleeing occupied Austria with his family. She made no effort to hide her disappointment at his results, and no one thought to point out that the entire test was written in English, a language the child was still working hard to learn. Seventy years later, looking back, the distinguished psychologist Walter Mischel did not rule out the possibility that this was the moment he developed a deep aversion to tests that try to define the wonderful complexity of personality in superficial and rigid ways.
There is a certain irony in the fact that Mischel later became famous in popular culture for a brilliantly simple test he conducted with kindergarteners at Stanford. He offered children a choice between one marshmallow now or two marshmallows later. The results were striking: children who managed to hold back and wait for the larger reward grew up to be more patient teenagers with stronger academic performance, and later into adults with fewer issues related to addiction, crime, and unemployment, compared to those who gave in and chose the immediate treat. But Mischel was careful not to conclude from this that our fate is sealed in childhood. He studied the strategies the successful children used to help themselves during the wait. The test videos and their various recreations became popular on YouTube precisely because of the creative methods children invented to resist temptation, carefully examining the ceiling, turning the marshmallow into a racing car zooming across the table, and more. The conclusion was an optimistic one: self-control is a strategy that can be learned and applied when needed, as long as the motivation and knowledge are there.
Walter Mischel is one of the towering figures of twentieth-century psychology. Given that psychology as a discipline is relatively young, dating back only to the late nineteenth century, Mischel ranks among the most important psychologists of all time. He played a central role in resolving a major debate that had divided researchers for decades: one side argued that every person has a relatively stable personality, a unique set of traits they are born with, so that someone can be described as “emotional” or “hot-tempered” in general. The other side championed situational determinism, the idea that innate traits are meaningless and that everything depends on the environment and the specific circumstances a person finds themselves in. Both camps dug in with supporting evidence, and the research world was divided for many years. After decades of study, Mischel proposed a solution that honored both sides: we are indeed born with certain character traits and genetic tendencies, but how and where they find expression depends entirely on the structure of our environment and the situations we encounter. The dominant CBT therapy practiced today was built on the foundations Mischel laid.
This is not a typical popular science book. Mischel mentored a generation of prominent psychologists who are active in the field today, and the book reads almost as a professional autobiography. With a personal touch and genuine humility, he recounts his experiments over the years and the work of his students, many of whom became important researchers in their own right. Across hundreds of experiments, a picture emerges of an ongoing struggle between two systems in the brain: one warm and impulsive, the other cool and rational, with each of us able to choose whether and when to engage the cooler system to achieve better outcomes. At its heart, the question facing every one of us is how much to sacrifice today for the sake of who we want to be tomorrow. Out of that tension between two versions of ourselves grows a fascinating story of self-control, cultural differences, human nature, genetics, and personal choice. The story spans nearly a hundred years of research, and the author, well into his eighties at the time of writing, still looked forward with the curiosity of that young immigrant boy from Brooklyn. It is very hard to read this book and remain unmoved.
