Peter H. Ditto

I am interested in "hot cognition" -- the interface between passion and reason. My research examines the role of motivation and emotion in social, political, moral, medical, and legal judgment. Most generally, my work has sought to explain the phenomenon of "motivated reasoning," or how the desire to reach a particular conclusion biases the processing of information related to that conclusion. My early work in this area examined the role such biases play in how people respond to threatening medical information (e.g., denial). More recently, my work has been focused on motivated moral reasoning, particularly how people selectively recruit general moral principles to support desired moral conclusions. Another key focus of my current research is on partisan political bias. This work examines the multiple ways that political ideology biases our political judgments and behavior. Finally, I am interested in a variety of psychological issues involved in end-of-life medical decision making. This work amounts to a psychological critique of policy encouraging the use of "living wills" in end-of-life medical decision making.

Web Links of Research Sites

• Research Opportunities (Undergraduate)
• Yourmorals.org (a research collaboration with Jonathan Haidt at the University of Virginia)

Web Links of Interest

•  Interdisciplinary Center for the Scientific Study of Ethics and Morality
• Civil Politics (an organization dedicated to constructive political dialogue)

Selected Publications

• Graham, J., Nosek, B. A., Haidt, J., Iyer, R., Koleva, S., & Ditto, P. H.  (in press).  Mapping the moral domain.  Journal of Personality and Social Psychology
• Iyer, R., Graham, J., Koleva, S., Ditto, P., Haidt, J.  (in press).  Beyond identity politics:  Moral psychology and the 2008 Democratic primary.  Analyses of Social Issues and Public Policy.
• Uhlmann, E. L., Pizarro, D.A., Tannenbaum, D., & Ditto, P. H.  (2009).  The motivated use of moral principles.  Judgment and Decision Making, 4, 476-491.
• Ditto P. H., & Mastronarde, A. J. (2009).  The paradox of the political maverick.  Journal of Experimental Social Psychology, 45, 295-298.
• Lench. H. C., & Ditto, P. H. (2008). Automatic optimism: Biased use of base rate information for positive and negative events. Journal of Experimental Social Psychology, 44, 631-639.
• Sharman, S. J., Garry, M., Jacobson, J. A., Loftus, E. F., & Ditto, P. H. (2008).  False memories of end-of-life decisions.  Health Psychology, 27, 291-296.
• Ditto, P. H. (2006). What would Terri want? On the psychological challenges of surrogate decision making. Death Studies, 30, 135-148.
• Ditto, P. H., Jacobson, J. A., Smucker, W. D., Danks, J. H., & Fagerlin, A. (2006). Context changes choices: A prospective study of the effects of hospitalization on life-sustaining treatment preferences. Medical Decision Making, 26, 313-322.
• Ditto, P. H., Pizarro, D. A., Epstein, E. B., Jacobson, J. A., & MacDonald, T. K. (2006). Visceral influences on risk taking behavior. Journal of Behavioral Decision Making, 19, 99-113.
• Ditto, P.H., & Hawkins, N. A. (2005). Cancer decision making near the end of life. Health Psychology, 24, S63-S70.
• Ditto, P. H., Hawkins, N. A., & Pizarro, D. A. (2005). Imagining the end of life: On the psychology of advance medical decision making. Motivation and Emotion, 29, 475-496.
• Hawkins, N. A., Ditto, P. H., Danks, J. A., & Smucker, W. D. (2005). Micromanaging death: Process preferences, values, and goals in end-of-life medical decision making. The Gerontologist, 45, 107-117.
• Ditto, P. H., Munro, G. D., Apanovich, A. M., Scepansky, J. A., & Lockhart, L. K. (2003). Spontaneous skepticism: The interplay of motivation and expectation in responses to favorable and unfavorable medical diagnoses. Personality and Social Psychology Bulletin, 29, 1120-1132.
• Munro, G. D., Ditto, P. H., Lockhart, L. K., Fagerlin, A., Gready, M., & Peterson, E. (2002). Biased assimilation of sociopolitical arguments: Evaluating the 1996 U.S. presidential debate. Basic and Applied Social Psychology, 24, 15-26.
• Ditto, P. H., Smucker, W. D., Danks, J. H., Jacobson, J. A., Houts, R. M., Fagerlin, A., Coppola, K. M., & Gready, R. M. (2003). The stability of older adults' preferences for life-sustaining medical treatment. Health Psychology, 22, 605-615.
• Coppola, K. M., Ditto, P. H., Danks, J. H., & Smucker, W. D. (2001). Accuracy of primary physicians' and hospital-based physicians' predictions of elderly outpatients' treatment preferences with and without advance directives. Archives of Internal Medicine, 161, 431-440.
• Ditto, P. H., Danks, J. H., Smucker, W. D., Bookwala, J., Coppola, K. M., Dresser, R., Fagerlin, A., Gready, R. M., Houts, R., Lockhart, L. K., & Zyzanski, S. (2001). Advance directives as acts of communication: A randomized controlled trial. Archives of Internal Medicine, 161, 421-430.
• Fagerlin, A., Ditto, P. H., Danks, J. H., Houts, R., & Smucker. W. D. (2001). Projection in surrogate decisions about life-sustaining medical treatment. Health Psychology, 20, 166-175.