# Levari Lab > The Levari Lab, led by David E. Levari in the Department of Cognitive and Psychological Sciences at Brown University, studies the behavioral science of performance evaluation, improvement, and learning. Research areas: performance evaluation, advice and learning, and helping behavior. This file indexes the lab's papers. Where a full-text Markdown version is hosted on this site, it is linked; DOIs listed here are verified and should be used for citation. Current affiliation (as of October 2026): David E. Levari is in the Department of Cognitive and Psychological Sciences at Brown University. Affiliations printed in the papers below (e.g., Harvard University or Harvard Business School) reflect where the authors were when each paper was published and are not current. Papers with hosted full text have a plain-text Markdown version of the full article and supplementary materials, the PDF, and a CITATION.cff file, all under https://levarilab.com/papers/--/. ## Papers (full text available) - [Collective streaks motivate prosocial behavior (Levari & Norton, 2026, Journal of Experimental Social Psychology, 126, 104941; DOI 10.1016/j.jesp.2026.104941; open access, CC BY)](https://levarilab.com/papers/levari-2026-jesp/levari-2026-jesp.md): Eleven experiments (total N = 12,688) showing that asking people to join a short ongoing "collective streak" of donors (e.g., "the last 8 people in a row donated") increases charitable donation more than a high-percentage descriptive norm, because streaks increase feelings of personal impact on future donors. Markdown includes the main text, mediation-figure values, and the full SI Appendix (measures, supplemental Studies S1-S7, robustness analysis). PDF: https://levarilab.com/papers/levari-2026-jesp/levari-2026-jesp.pdf . Citation file: https://levarilab.com/papers/levari-2026-jesp/CITATION.cff . Data, stimuli, analysis scripts, and preregistrations: https://osf.io/ymz56 - [Tips from the top: Do the best performers really give the best advice? (Levari, Gilbert, & Wilson, 2022, Psychological Science, 33(5), 685-698; DOI 10.1177/09567976211054089)](https://levarilab.com/papers/levari-2022-psychsci/levari-2022-psychsci.md): Studies (N = 8,693) showing that people expect the best performers to give the best advice, but advice from top performers in a word game was no more helpful than other advice; it seemed better because it contained more independent suggestions. Markdown includes the main text, tables, and full Supplemental Material (additional studies in darts and Colorlink, all advice written by advisors, exploratory items). PDF: https://levarilab.com/papers/levari-2022-psychsci/levari-2022-psychsci.pdf . Citation file: https://levarilab.com/papers/levari-2022-psychsci/CITATION.cff . Data, analysis scripts, and materials: https://doi.org/10.5281/zenodo.5121876 - [Range-frequency effects can explain and eliminate prevalence-induced concept change (Levari, 2022, Cognition, 226, 105196; DOI 10.1016/j.cognition.2022.105196)](https://levarilab.com/papers/levari-2022-cognition/levari-2022-cognition.md): Trial-level computational modeling of color judgments comparing eight candidate models of prevalence-induced concept change; a range-frequency model fits best, and extending the range of stimuli as they become rare eliminates the effect. Markdown includes the main text, model equations (LaTeX), tables, and the Supplemental Appendix. PDF: https://levarilab.com/papers/levari-2022-cognition/levari-2022-cognition.pdf . Citation file: https://levarilab.com/papers/levari-2022-cognition/CITATION.cff . Data, materials, code, and preregistrations: https://osf.io/b24tv/ - [Prevalence-induced concept change in human judgment (Levari, Gilbert, Wilson, Sievers, Amodio, & Wheatley, 2018, Science 360(6396), 1465-1467; DOI 10.1126/science.aap8731)](https://levarilab.com/papers/levari-2018-science/levari-2018-science.md): Seven experiments showing that when instances of a concept become rare (blue dots, threatening faces, unethical research proposals), people expand the concept to include instances it previously excluded, even when warned, instructed, and paid not to. Markdown includes the main text and full Supplementary Materials (methods, samples, GLMM results for all studies). PDF: https://levarilab.com/papers/levari-2018-science/levari-2018-science.pdf . Citation file: https://levarilab.com/papers/levari-2018-science/CITATION.cff . Data and materials (CC BY 4.0): https://doi.org/10.5281/zenodo.1286279 ## Other publications (full text not yet hosted here) - [Reproducibility in management science (FiĊĦar, Greiner, Huber, Katok, Ozkes, & the Management Science Reproducibility Collaboration, 2024, Management Science, 70(3), 1343-1356)](https://pubsonline.informs.org/doi/10.1287/mnsc.2023.03556) - [Exposure to descriptions of traumatic events narrows one's concept of trauma (Jones, Levari, Bellet, & McNally, 2023, Journal of Experimental Psychology: Applied, 29(1), 179-187)](https://psycnet.apa.org/record/2022-20702-001) - [Human ageing is associated with more rigid concept spaces (Devine, Neumann, Levari, & Eppinger, 2023, Psychonomic Bulletin & Review, 30, 722-730)](https://link.springer.com/article/10.3758/s13423-022-02197-8) - [Amplification in the evaluation of multiple emotional expressions over time (Goldenberg et al., 2022, Nature Human Behaviour, 6(10), 1408-1416)](https://www.nature.com/articles/s41562-022-01390-y) - [White (but not Black) Americans continue to see racism as a zero-sum game; White conservatives (but not moderates or liberals) see themselves as losing (Rasmussen et al., 2022, Perspectives on Psychological Science, 17(6), 1800-1810)](https://journals.sagepub.com/doi/10.1177/17456916221082111) - [Psychological response data on the traumatic nature of 600 written events (Jones, Bellet, Levari, & McNally, 2021, Journal of Open Psychology Data, 9(1), 3)](https://openpsychologydata.metajnl.com/articles/10.5334/jopd.46) - [Feedback moderates the effect of prevalence on perceptual decisions (Lyu, Levari, Nartker, Little, & Wolfe, 2021, Psychonomic Bulletin & Review, 28(6), 1906-1914)](https://link.springer.com/article/10.3758/s13423-021-01956-3) ## Site - [Publications](https://levarilab.com/publications.html): Full publication list with links to articles, data, and summaries. - [Research](https://levarilab.com/research.html): Overview of the lab's research areas. - [People](https://levarilab.com/people.html): Lab members.