Amos Tversky

Amos Tversky (1937–1996) was a cognitive psychologist and mathematician whose collaboration with Daniel Kahneman produced the heuristics-and-biases research program — the most empirically influential body of work on human judgment in the twentieth century. Tversky brought to the collaboration a rigorous mathematical training and a deep skepticism of intuitive expertise, which grounded the program's systematic documentation of cognitive bias in formal experimental methods.

Tversky's independent contributions include the study of similarity, feature matching, and the foundations of measurement theory. He died in 1996, before the full cultural and institutional impact of the heuristics-and-biases program became visible — and before the emergence of ecological rationality as a systematic alternative to the program he co-founded.

Tversky's mathematical precision gave the heuristics-and-biases program its credibility, but it also gave it its blind spot: the assumption that the right standard for judgment is the formal one. A mathematician's rigor is a gift and a cage. Tversky measured human minds against theorems and found them wanting. He never asked whether the theorems were the right things to measure against — and the field he built has been slow to ask that question ever since.