This Day in Jewish History

1937: A Psychologist Who Shed Light on Our Irrationality Is Born

Amos Tversky worked with Daniel Kahneman on the logic behind irrationality: No, a 'hot streak' in sports doesn't change probabilities.

Picture of Amos Tversky, psychologist and mathematician, on the backdrop of red dice: He helped show demonstrate why people hold irrational beliefs, for instance that a roulette wheel that has landed on red several times in a row is more likely to land on black the next around. It isn't.
Dreamstime.com and Wikimedia Commons

March 16, 1937, is the birthdate of psychologist and mathematician Amos Tversky. Although for professional colleagues, Tversky was an extraordinarily talented researcher who made many contributions in his own right before his death at age 59, but he’s best known among the general public for having been the associate of Daniel Kahneman. The research the two men did together on how people perceive economic decisions formed the basis for what developed into the field of behavioral economics.

When Kahneman won the Nobel Prize in Economics in 2002, he told The New York Times that “I feel it is a joint prize,” considering that, “[w]e were twinned for more than a decade.” (Rules for the Nobel Prizes prevent them from being awarded posthumously.)

Amos N. Tversky was born in Haifa, in pre-state Palestine. His father, Yosef Tversky, was a Polish-born veterinarian, and his mother, the former Jenia Ginzburg, was a Russian-born social worker, who, under her married name, served in the first through fifth Knessets (1951-1964) with Mapai, the predecessor to the Labor Party.

War hero scientist

Tversky served as a paratrooper in the Nahal Brigade, and reached the rank of captain. In 1956, he was badly wounded when he rescued a comrade who had panicked and frozen while planting an explosive. Tversky threw him to safety before the bomb detonated, and in the end was badly wounded himself. His action earned him a General’s Citation. He also fought in the Six-Day and Yom Kippur wars.

Tversky earned his bachelor’s degree in philosophy and psychology from the Hebrew University in 1961, and followed that with a doctorate in psychology from the University of Michigan, in 1965.

He and Kahneman began working together when both were teaching at the Hebrew University, in 1969.

The older Kahneman asked Tversky – whom he describes as “brilliant, voluble, and charismatic,” in “Thinking: Fast and Slow” – to address the psychology seminar he was then teaching. Tversky talked to the students about statistical intuition – people’s intuitive grasp of principles of statistics.This in turn led him and Kahneman to write a paper together, which was the start of14 years of collaborative research.   

Do you know Tversky is smarter than you?

“Amos was always very funny,” writes Kahneman, “and in his presence I became funny as well, so we spent hours of solid work in continuous amusement.”

Tversky and Kahneman developed what they called “prospect theory,” which was an attempt to quantify people’s irrational economic choices.

Standard economic theory that relies on the rationality of markets failed to consider that people perceive questions of probability, for example, in ways that are not strictly rational, and that the way a question is framed can affect the way it is understood. What prospect theory did was to find the rational patterns that characterized people’s “cognitive illusions.”

Some colleagues later devised what they called the “Tversky Intelligence Test,” by which, as Malcolm Gladwell quoted a former colleague of Tversky’s in his book “David and Goliath,” "The faster you realized Tversky was smarter than you, the smarter you were."

Whether it was studying the common belief that basketball players on an apparent hot streak are really more likely to continue sinking baskets (they’re not, Tversky proved), or whether a roulette wheel that has landed on red several times in a row is more likely to land on black the next around (it’s not, as the chances of that happening on any individual spin remain 50:50), the two wanted to understand the science behind people’s false intuitions.

Tversky also observed how, when weighing risks and benefits in making decisions, people tend to place greater emphasis on risks, as they are especially averse to paying a price. The corollary to this is that, restating the same question in a way that highlights the risk (describing a 50 percent chance of losing, as opposed to a 50 percent probability of winning) can affect the decision one makes regarding that question.

Tversky became a professor of behavioral science at Stanford University in 1978, where his wife, the former Barbara Gans, a cognitive scientist, also had an appointment. He died of metastatic melanoma on June 2, 1996.