Thomas Dashiff Gilovich (born January 16, 1954) is an American psychologist who is the Irene Blecker Rosenfeld Professor of Psychology at Cornell University.

He has conducted research in social psychology, decision making, and behavioral economics, and has written popular books on these subjects.

He describes his research as dealing with "how people evaluate the evidence of their everyday experience to make judgments, form beliefs, and decide on courses of action, and how they sometimes misevaluate that evidence and make faulty judgments, form dubious beliefs, and embark on counterproductive courses of action.

Writing in Skeptical Inquirer, Carl Sagan called it "a most illuminating book" that "shows how people systematically err in understanding numbers, in rejecting unpleasant evidence, in being influenced by the opinions of others.

[13] Some of the research from the 1985 paper has been contested recently, with a new journal article arguing that Gilovich and his coauthors themselves fell victim to a cognitive bias in interpreting the data from the original study.

"[15] For the paper, Gilovich and his coauthors conducted an experiment asking college students to put on a Barry Manilow shirt and walk into a room of strangers facing the door.

The results were as predicted, with participants thinking that roughly half the strangers would have recognized the Barry Manilow shirt, when in fact the number was closer to 20 percent.

[20] Building on his research on the spotlight effect, Gilovich helped to discover the illusion of transparency, or the tendency to overestimate the extent to which people telegraph their inner thoughts and emotions.

However, because each individual holds back, looks nonchalant, and monitors the reactions of others, sometimes everyone concludes (perhaps erroneously) that the situation is not an emergency and hence does not require intervention.

[25] In his social psychology research, Gilovich discovered the phenomenon of self-handicapping, which he described as "attempts to manage how others perceive us by controlling the attributions they make for our performance."

An example of self-handicapping, according to Gilovich, would be drawing attention to elements that inhibit performance, and so discount failure in others' eyes, or make success the result of overcoming insurmountable odds.

The self-handicapping can either be real (failing to study or drinking excessively), or faked (merely claiming that there were difficult obstacles present).

Gilovich has written a popular book condensing his academic research in the field, and which touches on many of the topics in How We Know What Isn't So, The Wisest One in the Room: How You Can Benefit from Social Psychology's Most Powerful Insights.

In an interview with Brian Lehrer, Gilovich discussed the book and the subjects it touches on, such as the difference between intelligence and wisdom, the latter being knowledge of other people and how to connect with them, the negative impact of income inequality on happiness, motivation, and what can create "virtuous cycles" in a university environment.

"[27] A major recurring theme in Gilovich's work in behavioral economics is the importance of experience over ownership of material things.

"[28] Writing for The Atlantic, James Hamblin noted the growing body of research, pioneered by Gilovich, showing that experiences tend to bring people more happiness than possessions: "It's the fleetingness of experiential purchases that endears us to them.