Daniel Kahneman’s death at the age of 90 left a huge void in the field of behavioral science and the broader intellectual community.
His scientific contributions, many in collaboration with cognitive psychologist Amos Tversky, transformed the disciplines of psychology and economics. They also had a major impact on philosophy, political science, and many other disciplines.
I first met Danny in 1984 when I was a student. I moved to Vancouver, Canada, to work with psychologist Ann Triesman in her shared laboratory at the University of British Columbia. Although Danny was not yet as famous as he would become, his genius was widely recognized.
Three then or future Nobel laureates visited the class. Young Richard Thaler spent a year with us, and Thomas Schelling and Francis Crick also came. Despite this, Danny had time for everyone. Sometimes I find myself giving the same advice Danny gave me to my students and colleagues to this day.
In 2002, Danny received the Nobel Memorial Prize in economic sciences. He later became perhaps the most influential and distinguished writer to the public in the field of behavioral sciences (rivalling his close friend and collaborator Richard Thaler). Danny’s 2011 book Thinking, Fast and Slow is a classic of popular science writing.
In it he popularized and developed the idea of two systems of thought. One of the two systems is fast, efficient, confident, and error-prone (system one), while the other is slow, resource-hungry, full of doubts, and perhaps a little less error-prone (system two).
These systems work together. The first system tells us that dessert is probably delicious and worth considering, while the second system (might) kick in to control the number of calories before we get into it.
It may be difficult to pinpoint Danny’s most important contributions in academia, but his expectancy theory, which he introduced with Tversky in 1979, is by far the most cited theory. The paper challenged the mainstream economic view that people are fundamentally “rational,” even if they are prone to error.
Many scientists realized that this could not be entirely true. But Danny and Tversky showed that incorporating important psychological principles into economics could explain many puzzling observations about human nature.
Impulse psychology
The prospect theory paper also provided more than a dozen experimental demonstrations for its claims. Teachers (like me) still use these demonstrations in the classroom, so reliable are the results they report.
A simple example: given a choice between a sure bet of winning £100 and a 50/50 chance of winning £200, most people will take the £100. But given a choice between a sure loss of £100 and a 50/50 chance of losing £200, people will take the 50/50 chance. People are risk averse when it comes to gains, but they are risk seeking when it comes to losses.
Expectancy theory continues to generate new research and forms the basis of the science of “nudges.” Nudge theory is the idea that our behavior can be successfully influenced by “soft” interventions. One of its core principles is loss aversion; This means that people are more sensitive to losses than to gains of equivalent size.
If you want people to bring their own cups to a cafe, charging them for a paper cup (loss) is more effective than giving them a discount for bringing their own cups (gain). The idea that behavior can be influenced by such biases is now part of the bread and butter of behavioral science.
Other findings of expectancy theory included people’s tendency to “fixate” when making quantitative judgments. For example, if you make an offer on a house, the seller’s evaluation will likely sway in the direction of your offer. Danny also described the planning fallacy, the tendency for projects to cost more, deliver less, and take longer than expected.
Another fascinating work by Danny examined how a person’s feelings and judgments about events depend on imagined alternatives to those events. One way the imagination works is to “undo” events. The easier they are to undo, the greater their impact on us. This rule was central to norm theory, a 1986 paper he wrote with Dale Miller.
An example of how retrieval works: If a car crashes into a wall one meter from where we are standing, we believe we missed being killed and are relieved. But if tomorrow a car crashed into the exact spot where we are standing today, we would probably give it less thought. Our imagination does not automatically create a scenario where we are standing one meter to the left now, but will stand in the same place tomorrow.
welfare science
Danny also pioneered the welfare analysis. Our thoughts about an experience are more likely to be influenced by our interpretation of an experience than by the positive or negative emotions we have during it.
For example, the climax rule is that how much we enjoy a past experience depends on the best or worst part of that experience and how it ended. Danny showed that men receiving colonoscopy would report a better experience if the painful intervention had a longer period of moderate pain, rather than a period that ended earlier but resulted in greater pain.
One of the aspects that distinguishes Danny from other researchers is that his work is driven by the desire to not only contribute to a field of research, but also to create new ones. And then, if possible, answer all the questions they ask. Therefore, even though it was published decades ago, his research continues to provide the basis for new ideas and debates.
I last met Danny less than a year ago. I visited his home in New York for dinner. At one point in the evening, Danny said people came to see him to say goodbye.
His eyes were smiling and he raised his hand as he said this; It was a smile and gesture I had seen him use many times; It was a mix of “I don’t take offense”, “You shouldn’t be offended by my frankness” and “Let me”. “Let me explain.” I didn’t want to face what he said, but I understood. His eyes were open about the possibility of death. He wasn’t afraid of death, he wasn’t afraid of anything.
This article is republished from The Conversation under a Creative Commons license. Read the original article.
Daniel Read does not work for, consult, own shares in, or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond his academic duties.