Ruben Lennartz

Ruben Lennartz is Professor at the Chair of Psychological Research Methods.

Psychology still is a young science. Memorising important facts will not get you very far. The findings from your studies may soon be outdated. At the same time, scientific claims to knowledge compete with the everyday intuitive insights we gather, as well as the narratives and interpretations presented to us by the media. That is why it is particularly important for psychologists to be able to critically evaluate and classify evidence and studies. In our teaching, we impart the tools of critical thinking and invite discussion. We explore weaknesses in psychological knowledge acquisition, conduct research on research, and develop tools to conduct better research. In terms of content, we focus primarily on observational, non-experimental data at the interface between psychology and biology. In terms of policy, we are committed to greater transparency in research and a more open culture of error.

One of the main focuses of our research is metascience, i.e. research about research. 

Three current projects:
DFG META-REP SYNTH: Evaluating Transformer Models to Generate Synthetic Replications, Nomological Nets, and Peer Reviews (#546323839). Here, we aim to use large language models to regain an overview of our discipline and our jumble of measuring instruments and abstract constructs.
www.lmu.de/psy/de/forschung/meta-rep/projects-1.fp/

DFG META-REP SOBER: Standardisation of Behaviour Research Methods. In this project, we focused on the development, improvement, and dissemination of measurement standards in psychology, including the more efficient standardisation of psychological testing procedures and the curbing of construct proliferation in psychology. 
www.lmu.de/psy/de/forschung/meta-rep/projects-2.fp/

ERROR. In the ERROR project, we search for errors in frequently cited, published, peer-reviewed studies. We want to reform the culture of error in psychology so that mistakes are more easily admitted and corrected. 
error.reviews

In methodological research, we focus primarily on the pitfalls and strengths of common measurement methods, from subjective self-assessments to steroids in saliva. Only when we understand the limitations of our measurement instruments and model them statistically correctly can we obtain reliable insights into the underlying reality.

We also develop tools for improved data collection (https://formr.org) and documentation (https://rubenarslan.github.io/codebook/).

The focus of our research is on individual differences at the disciplinary boundary between psychology and biology. Current research topics include individual differences in hormonal fluctuations throughout the menstrual cycle and, related to this, differences in the effectiveness of hormonal contraception.

• Annika Külpmann 

04/2025 – present
Chair holder
Professorship for Psychological Research Methods
Witten/Herdecke University

04/2021 – 03/2025
Research assistant
Personality Psychology and Psychological Diagnostics
University of Leipzig

10/2017 - 03/2021
Research Assistant
Centre for Adaptive Rationality
Max Planck Institute for Human Development, Berlin

10/2013 - 10/2017
Doctorate (Dr. rer. nat.)
Topic: Secular changes in sexual and natural selection against harmful genetic mutations in humans
Georg August University of Göttingen

10/2013 - 09/2017
Research assistant
Biological Personality Psychology
University of Göttingen

03/2016
Research stay at the Centre for Interdisciplinary Research, Bielefeld.
Group: Genetic and social causes of life chances

10/2008 - 09/2013
Diploma in Psychology 
Thesis title: The effect of paternal age on the intelligence of offspring and other characteristics when controlling for paternal trait levels.
Humboldt University of Berlin

09/2011 - 10/2011
Internship at the University of Edinburgh

06/2010 - 09/2013
Student assistant in the DFG project Self-Insight & Laboratory for Personality Development
Humboldt University of Berlin

• Bachelor's degree: Psychological research methods
• Master's degree: Multivariate research methods, Advanced psychological principles (opportunities, equality and genetics)

Hormonal fluctuations throughout the cycle, psychological side effects of hormonal contraception, paternal effects, meta-science, error culture, methodological assessments, genetic effects on intelligence and personality

Co-blog: The 100% CI: the100.ci

Personal blog: rubenarslan.github.io

Member of the German Psychological Society (DGPs), sections:

• Biological Psychology and Neuropsychology
• Differential and Personality Psychology and Diagnostics
• Methods and Evaluation

Connect
https://x.com/rubenarslan 

https://bsky.app/profile/ruben.the100.ci 

https://www.linkedin.com/in/ruben-arslan/ 

https://scholar.google.com/citations?user=X6fXzMcAAAAJ&hl=en