Daniel Kahneman, a psychologist who pioneered theories in behavioural economics that heavily influenced the discipline, and won him a Nobel prize, has died at age 90.

Kahneman, who wrote bestselling book Thinking, Fast and Slow, argued against the notion that people’s behaviour is rooted in a rational decision-making process – rather that it is often based on instinct.

Kahneman’s employer, Princeton University, where the Israeli-American academic worked until his death, confirmed his death on Wednesday in a statement on its website.

“Many areas in the social sciences simply have not been the same since he arrived on the scene,” Prof Eldar Shafir, a former colleague, said in a press release. “He will be greatly missed.”

In 2002, Kahneman was awarded the Nobel memorial prize in economic sciences in recognition for his research in the fields of psychology and economics.

Described by Steven Pinker as “the world’s most influential living psychologist”, Kahneman’s most popular theory opposed traditional economic approaches that people were fully rational and self-interested.

Instead, the theory argued that people have mental biases that can distort their judgments.

“I had limited ambitions, I didn’t aspire to great success,” Kahneman told the Guardian in 2015. “I was very hardworking, but I didn’t expect to be a famous psychologist.

“I’m quite capable of great enjoyment, and I’ve had a great life.”

With Agence France-Presse