Research

Tips from the top: Do the best performers really give the best advice?

Levari, D.E., Gilbert, D.T., & Wilson, T.D. (2022). Tips From the Top: Do the Best Performers Really Give the Best Advice?. Psychological Science, 33(5), 685-698. [read] [data/materials/code]

Everyone knows that if you want to learn how to do something, you should get advice from people who do it well. But is everyone right? In a series of studies (N = 8,693), adult participants played a game after receiving performance advice from previous participants. Although advice from the best-performing advisors was no more beneficial than advice from other advisors, participants believed that it had been—and they believed this despite the fact that they were told nothing about their advisors’ performance. Why? The best performers did not give better advice, but they did give more of it, and participants apparently mistook quantity for quality. These studies suggest that performing and advising may often be unrelated skills and that in at least some domains, people may overvalue advice from top performers.

Range-frequency effects can explain and eliminate prevalence-induced concept change

Levari, D.E. (2022). Range-frequency effects can explain and eliminate prevalence-induced concept change. Cognition, Volume 226. [email me for a copy] [data/materials/code]

Why would concepts seem to grow when their instances become rare? Human observers can respond to decreases in stimulus prevalence by expanding their conceptual boundaries of those stimuli. This prevalence-induced concept change may have serious social consequences, since many real-world detection tasks demand consistent judgments over time. The current work aims to identify the computational process that produces prevalence-induced concept change. I review some plausible models from the cognitive and social sciences that could account for this phenomenon, and then use trial-level computational modeling to see how well each model predicts actual human data, finding that they are best explained as a range-frequency compromise in judgment. Finally, I test an intervention that successfully eliminates prevalence-induced concept change by making stimuli more intense as they become rare.

Prevalence-induced concept change in human judgment

Levari, D.E., Gilbert, D.T., Wilson, T.D., Sievers, B., Amodio, D.M., & Wheatley, T. (2018). Prevalence-induced concept change in human judgment. Science, 360(6396), 1465–1467. [read] [data/materials/code]

Why do some social problems seem so intractable? In a series of experiments, we show that people often respond to decreases in the prevalence of a stimulus by expanding their concept of it. When blue dots became rare, participants began to see purple dots as blue; when threatening faces became rare, participants began to see neutral faces as threatening; and when unethical requests became rare, participants began to see innocuous requests as unethical. This “prevalence-induced concept change” occurred even when participants were forewarned about it and even when they were instructed and paid to resist it. Social problems may seem intractable in part because reductions in their prevalence lead people to see more of them.