Dr. Kathi Diel

Dr. Kathi Diel

Research Interests

My research focuses on social comparison processes, particularly their role in goal motivation and their link to emotions that shape goal pursuit (e.g., guilt, pride, envy). A key aspect of my work goes beyond simply distinguishing between comparison direction (upward vs. downward) by also considering comparison extremity – the extent to which a person deviates from a given standard. This allows me to examine how comparison direction and extremity influence motivational tendencies stemming from self-regulation research—pushing, coasting, and disengagement. My research findings suggest that upward comparisons are linked to enhanced self-improvement motivation (pushing), but this effect is nonlinear (Diel et al., 2021). Upward comparisons are associated with pushing when the standard is moderate, meaning the standard is slightly ahead and thus attainable, but this effect diminishes when the standard is extreme and out of reach. In contrast, extreme upward comparisons are more likely to be linked to goal disengagement (i.e., giving up). Downward comparisons, on the other hand, tend to be associated with reduced effort investment, as people feel they have already done enough (coasting). In addition to these findings, I use intervention studies to explore whether guided upward or downward comparisons can actively shape motivation, emotions, and ultimately goal attainment in everyday life (Diel et al., 2024).

Another area of my research focuses on environmental psychology. I investigate how people engage in climate action and how different pro-environmental behaviors interact, such as through spillover, where one pro-environmental behavior increases the likelihood of another, or licensing effects, where prior pro-environmental behavior justifies less pro-environmental choices.

Additionally, I investigate social comparison dynamics in the context of climate action. Since environmental behavior is strongly tied to morality, people often engage in downward comparisons instead of upward comparisons to maintain a positive moral self-image (Diel & Friese, 2024). My research examines the motivational consequences of this downward comparison tendency, particularly whether frequent downward comparisons lead to more coasting and thus reduced effort in climate action, as people may feel they have already done enough. I also investigate the conditions under which people may shift from downward to more attainable upward comparisons, which could enhance their motivation to adopt more pro-environmental behaviors.

Publications

Diel*, K., Boecker*, L., Lange, J., Hofmann, W., & Crusius, J. (in press). Emotional Dynamics of Social Comparisons: Nonlinear Relationships Between Comparison Extremity and Social Emotions, and Their Motivational Functioning. Personality and Social Psychology Bulletin.

Diel, K., Hofmann, W., Grelle, S., Boecker, L., & Friese, M. (in press). Prepare to compare: Effects of an intervention involving upward and downward social comparisons on goal pursuit in daily life. Personality and Social Psychology Bulletin. https://doi.org/10.1177/01461672231219

Diel, K., & Friese, M. (2024). Morally charged: Why people prefer to compare themselves with others who are less environmentally friendly than themselves. Journal of Environmental Psychology. https://doi.org/10.1016/j.jenvp.2024.102318

Vlasceanu, M., Doell, K. C., Bak-Coleman, J. B., Todorova, B., Berkebile-Weinberg, M. M., Grayson, S. J.,.... Diel...., K., & Lutz, A. E. (2024). Addressing climate change with behavioral science: A global intervention tournament in 63 countries. Science Advances, 10(6), eadj5778. 
http://doi.org/10.1126/sciadv.adj5778

Doell, K. C., Todorova, B., Vlasceanu, M., Bak-Coleman, J. B., Pronizius, E., Schumann, P., ... Diel, K.....,& Lutz, A. E. (2024). The International Climate Psychology Collaboration: Climate change-related data collected from 63 countries. Scientific Data, 11(1), 1066. https://doi.org/10.1038/s41597-024-03865-1

Unkelbach, C., Alves, H., Baldwin, M., Crusius, J., Diel, K., Galinsky, A. D., Gast, A., Hofmann, W., Imhoff, R., Genschow, O., Lammers, J., Pauels, E., Schneider, I. K., Topolinski, S., Westfal, M., & Mussweiler, T. (2023). Relativity in social cognition: Basic processes and novel applications of social comparisons. European Review of Social Psychology. https://doi.org/10.1080/10463283.2022.2161043

Diel*, K., Broeker*, L., Raab, M., & Hofmann, W. (2021). Motivational and emotional effects of social comparison in Sports. Psychology of Sport and Exercise, 57, 102048. https://doi.org/10.1016/j.psychsport.2021.102048

Diel, K., Grelle, S., & Hofmann, W. (2021). A motivational Framework of social comparison. Journal of Personality and Social Psychology, 120(6), 1415-1430. https://doi.org/10.1037/pspa0000204

Fleischmann, A., Lammers, J., Diel, K., Hofmann, W., & Galinsky, A. D. (2021). More threatening and more diagnostic: How moral comparisons differ from social comparisons. Journal of Personality and Social Psychology. https://doi.org/10.1037/pspi0000361

Vohs, K. D., Schmeichel, B. J., Lohmann, S., Gronau, Q. F., Finley, A. J., Ainsworth, S. E.,... Diel, K...., & Albarrac´ın, D. (2021). A multisite preregistered paradigmatic test of the ego-depletion effect. Psychological Science, 32(10), 1566-1581. https://doi.org/10.1177/0956797621989733

Hofmann, W., Dohle, S., & Diel, K. (2020). Changing behavior using integrative self-control theory. In: M. S. Hagger, L. D. Cameron, K. Hamilton, N. Hankonen, & T. Lintunen (Eds.), The handbook of behavior change (pp. 150 - 163). Cambridge: Cambridge University Press.

Rom, S.C., Katzir, M., Diel, K., & Hofmann, W. (2019). On trading off labor and leisure: a process model of perceived autonomy and opportunity costs. Motivation Science. https://doi.org/10.1037/mot0000148

Diel, K., & Hofmann, W. (2019). Inspired to perspire: The predicted interplay of social comparison direction and standard extremity in the context of challenging exercising goals. Social Cognition, 37, 247-265. https://doi.org/10.1521/soco.2019.37.3.247

Dohle, S., Diel, K., & Hofmann, W. (2018). Executive functions and the self-regulation of eating behavior: A review. Appetite, 124, 4-9. https://doi.org/10.1016/j.appet.2017.05.041

Hofmann, W., Diel, K., & Seibel, M. (2018). Foods, sex, and drugs: Appetitive desires and subjective well-being. In E. Diener & S. Oishi (Eds.), Handbook of well-being. Salt Lake City, UT: DEF Publishers.

*shared first authorship.