PEACH: Personality Detection and Digital Personality Coaching

Research has shown that personality traits are changeable over longer time periods, and that changes may bring about positive life outcomes such as greater success in work and family, better health, and longevity. Research also found that most people want to change or modify some aspects of their personality. However, less is known about the short-term changeability of personality traits.

The main aim of the planned research program is to test the efficacy of a smartphone-based intervention for intentional personality change using a novel open source platform that supports the design of evidence-based, scalable and low-cost interventions (; Filler et al. 2015; Kowatsch et al. 2017). The research strategy is threefold: (1) to develop a smartphone-based intervention to change personality traits, (2) to examine its efficacy to change personality traits in the desired direction, and (3) to examine underlying processes and mechanisms in an effort to improve the intervention outcomes.

This proposed research is the first testing the efficacy of a smartphone-based intervention for intended personality change. Given that this novel intervention approach proves effective, it could be easily implemented in various non-clinical settings and could reach large numbers of people due to its low-threshold character and technical scalability. The project is innovative from a personality psychology point of view as it examines the short-term changeability of personality traits, from a psychological intervention perspective as it applies a new generic intervention model, and from an information systems perspective as it investigates how mobile sensor services and anthropomorphic conversational agents must be designed to effectively deliver individualized interventions in real life and real time.

Project website:

The PEACH App and its components are shown in the following figure. Note: Chat-based interaction with the conversational agent PEACH (left), the sidebar (middle) that allows participants to switch to either a dashboard with a personalized overview of the current status of the intervention (right), a media library used for psychoeducational video clips, a chat channel that allows participants to communicate with the “Support-Team”, or a page for frequently asked questions about the PEACH study and the app.

Video Clips

©2017 Dynage Film Productions and University of Zurich, Personality Change team: Marcel Lauber, Mirjam Stieger, Thierry Haenggi, Charlotte Grimmel, Dave Haeusler, Stefan Wittwer, Andrea Trueb, Sina Hemmann, Roman Lickel, Rita Kamber, Pascal Fischer & Mathias Allemand. All rights reserved.

The PEACH Flyer



Lindner, S., Stieger, M., Rüegger, D., Kowatsch, T., Flückiger, C., Mehl, M.R., Allemand, M. (2023) How Is Variety in Daily Life Related to the Expression of Personality States? An Ambulatory Assessment Study, European Journal of Personality, 10.1177/08902070221149593


Olaru, G., Stieger, M., Rüegger, D., Kowatsch, T., Flückiger, C., Roberts, B.W., Allemand, M. (2022) Personality Change Through a Digital-Coaching Intervention: Using Measurement Invariance Testing to Distinguish Between Trait Domain, Facet and Nuance Change, European Journal of Personality, Online First 10.1177/08902070221145088.

Nißen, M.K., Rüegger, D., Stieger, M., Flückiger, C., Allemand, M., von Wangenheim, F., Kowatsch, T. (2022) The Effects of Health Care Chatbot Personas With Different Social Roles on the Client-Chatbot Bond and Usage Intentions: Development of a Design Codebook and Web-Based Study, Journal of Medical Internet Research (JMIR) 24(4):e32630, 10.2196/32630.


Stieger, M., Flückiger, C., Rüegger, D., Kowatsch, T., Roberts, B.W., Allemand, M. (2021) Changing Personality Traits with the Help of a Digital Personality Change Intervention, Proceedings of the National Academy of Sciences of the United States of America (PNAS) 118(8):e2017548118 10.1073/pnas.2017548118


Rüegger, D., Stieger, M., Nißen, M.K., Allemand, M., Fleisch, E., Kowatsch, T., How Are Personality States Associated with Smartphone Data?, European Journal of Personality 34(5) Special Issue: Behavioral personality science in the age of big data, 687-713 10.1002/per.2309.

Stieger, M., Eck, M., Rüegger, D., Kowatsch, T., Flückiger, C., Allemand, M. (2020) Who Wants to Become More Conscientious, More Extraverted, or Less Neurotic With the Help of a Digital Intervention, Journal of Research in Personality, (PDF)

Stieger, M., Wepfer, S., Rüegger, D., Kowatsch, T., Roberts, B.W., Allemand, M. (2020) Becoming More Conscientious or More Open to Experience? Effects of a Two-Week Smartphone-Based Intervention for Personality Change, European Journal of Personality 34(3), 345-366,


Stieger, M., Nißen, M.K., Rüegger, D., Kowatsch, T., Flückiger, C., Allemand, M. (2018) PEACH, a smartphone- and conversational agent-based coaching intervention for intentional personality change: study protocol of a randomized, wait-list controlled trial, BMC Psychology 6(43), pp. 1-15. (PDF)

Kowatsch, T., M. K. Nißen, D. Rüegger, M. Stieger, C. Flückiger, M. Allemand and F. von Wangenheim (2018) The Impact of Interpersonal Closeness Cues in Text-based Healthcare Chatbots on Attachment Bond and the Desire to Continue Interacting: An Experimental Design, 26th European Conference on Information Systems (ECIS 2018), Portsmouth, UK. PDF

Rüegger, D., Stieger, M., Flückiger, C., Allemand, M., Kowatsch, T. (2017) Leveraging the Potential of Personality Traits for Digital Health Interventions: A Literature Review on Digital Markers for Conscientiousness and Neuroticism, 11th Mediterranean Conference on Information Systems (MCIS), Genoa, Italy. PDF

Rüegger, D., Kowatsch, T., Stieger, M., Allemand, M. (2016) Unobtrusive Recognition of Personality Traits with Health Impact: A Literature Review with a Focus on Conscientiousness and Neuroticism, Proc. of the 10th Mediterranean Conference on Information Systems (MCIS) – Extended Abstract & Poster, Paphos, Cyprus. PDF

Related Work

Kowatsch, T., Volland, D., Shih, I., Rüegger, D., Künzler, F., Barata, F., Filler, A., Büchter, D., Brogle, B., Heldt, K., Gindrat, P., Farpour-Lambert, N., l’Allemand, D. (2017) Design and Evaluation of a Mobile Chat App for the Open Source Behavioral Health Intervention Platform MobileCoach, In: Maedche A., vom Brocke J., Hevner A. (eds) Designing the Digital Transformation. DESRIST 2017. Lecture Notes in Computer Science, vol 10243. Springer: Berlin; Germany, 485-489. (Paper-PDF | Poster-PDF | Slide-PDF | Screencast)

Wahle, F., L. Bollhalder, T. Kowatsch and E. Fleisch (2017) Toward the Design of Evidence-Based Mental Health Information Systems for People With Depression: A Systematic Literature Review and Meta-Analysis. Journal of Medical Internet Research 19 (5), e191. (PDF)

Filler, A., Kowatsch, T., Haug, S., Wahle, F., Staake, T. & Fleisch, E. (2015) MobileCoach: A Novel Open Source Platform for the Design of Evidence-based, Scalable and Low-Cost Behavioral Health Interventions – Overview and Preliminary Evaluation in the Public Health Context. Wireless Telecommunications Symposium 2015 (WTS 2015), New York, USA. ***Outstanding Paper Award & Best Graduate Student Paper Award*** PDF

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CDHI Research Team

Dominik Rüegger, Marcia Nießen, Florian Künzler, Prof. Dr. Elgar Fleisch, Prof. Dr. Tobias Kowatsch


CHF 480’000


Mar 2016 – May 2021


Mirjam Stieger, Prof. Dr. Mike Martin, Prof. Dr. Christoph Flückiger & Prof. Dr. Mathias Allemand (University of Zurich), Varun Mishra & Prof. David D. Kotz, PhD (Dartmouth College)

The Swiss National Science Foundation (SNSF)