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PhD Defense of Marcell Szekely

Marcell Székely
Thursday, June 15, 2023, 1:00 pm – 6:00 pm

You are cordially invited to the Defense of PhD thesis


Functional and Proximal Mechanisms of Effort Matching in Joint Action


Marcell Székely

Primary supervisor: Gunther Knoblich
Secondary supervisor: John Michael

Thesis submitted to:
Central European University, Department of Cognitive Science

Human life is woven through joint action. We organize governments, run businesses, conduct research projects, co-parent children and create music together. In recent years, considerable research has been devoted to investigating the psychological mechanisms which support this. One key finding is that people frequently calibrate their effort level to match a joint action partner’s effort - but it is not clear why they do so. In this dissertation, I aim to clarify a fundamental question: Why do people match their joint action partners’ effort? Specifically, I ask why evolution would have equipped us with such a tendency, and what the proximate psychological mechanisms are that underpin it.
Across Chapters 2-5, I present a range of empirical studies that bear upon these
questions. In Chapter 2, I address a prerequisite condition for effort matching. In particular, in order to calibrate our effort to that of others, we need to have the capacity to estimate the effort costs that observed agents are currently investing in specific ongoing activities. Therefore, in Chapter 2, I identify some of the relevant factors that feed into adults’ judgments about the level of others’ effort. Then, in Chapters 3-4, I investigate a battery of hypotheses about the evolutionary functions which may explain why people match their joint action partners’ effort,
as well as a battery of hypotheses about the proximate psychological mechanisms underpinning this behavior. Finally, in Chapter 5, I investigate the extent to which insights gained from research investigating how people distribute rewards can be generalized to scenarios in which people make decisions about how to distribute effort costs.