Luke McEllin’s research while affiliated with University of Vienna and other places

A novel, interdisciplinary exploration of the relative contributions of rigidity and flexibility in the adoption, maintenance, and evolution of technical traditions. Techniques can either be used in rigid, stereotypical ways or in flexibly adaptive ways, or in some combination of the two. The Evolution of Techniques, edited by Mathieu Charbonneau, addresses the impacts of both flexibility and rigidity on how techniques are used, transformed, and reconstructed, at varying social and temporal scales. The multidisciplinary contributors demonstrate the important role of the varied learning contexts and social configurations involved in the transmission, use, and evolution of techniques. They explore the diversity of cognitive, behavioral, sociocultural, and ecological mechanisms that promote and constrain technical flexibility and rigidity, proposing a deeper picture of the enablers of, and obstacles to, technical transmission and change. In line with the extended evolutionary synthesis, the book proposes a more inclusive and materially grounded conception of technical evolution in terms of promiscuous, dynamic, and multidirectional causal processes. Offering new evidence and novel theoretical perspectives, the contributors deploy a diversity of methods, including ethnographies, field and laboratory experiments, cladistics and phylogenetic tree building, historiography, and philosophical analysis. Examples of the wide range of topics covered include field experiments with potters from five cultures, stability and change in Paleolithic toolmaking, why children lack flexibility when making tools, and cultural techniques in nonhuman animals. The volume's three thematic sections are: • Timescales of technical rigidity and flexibility • Rigid copying to flexible reconstruction • Exogenous factors of technical rigidity and flexibility The volume closes with a discussion by philosopher Kim Sterelny. Contributors Rita Astuti, Adam Howell Boyette, Blandine Bril, Josep Call, Mathieu Charbonneau, Arianna Curioni, Nicola Cutting, Bert De Munck, György Gergely, Anne-Lise Goujon, Ildikó Király, Catherine Lara, Sébastien Manem, Luke McEllin, Helena Miton, Giulio Ongaro, Sarah Pope-Caldwell, Valentine Roux, Manon Schweinfurth, Dan Sperber, Kim Sterelny, Dietrich Stout, James W. A. Strachan, Sadie Tenpas

Benefiting from a cooperative interaction requires people to estimate how cooperatively other members of a group will act so that they can calibrate their own behavior accordingly. We investigated whether the synchrony of a group’s actions influences observers’ estimates of cooperation. Participants (recruited through Prolific) watched animations of actors deciding how much to donate in a public-goods game and using a mouse to drag donations to a public pot. Participants then estimated how much was in the pot in total (as an index of how cooperative they thought the group members were). Experiment 1 ( N = 136 adults) manipulated the synchrony between players’ decision-making time, and Experiment 2 ( N = 136 adults) manipulated the synchrony between players’ decision-implementing movements. For both experiments, estimates of how much was in the pot were higher for synchronous than asynchronous groups, demonstrating that the temporal dynamics of an interaction contain signals of a group’s level of cooperativity.

Depersonalization is a common and distressing experience characterized by a feeling of estrangement from one’s self, body, and the world. In order to examine the relationship between depersonalization and selfhood we conducted an experimental study comparing processing of three types of self-related information between nonclinical groups of people experiencing high and low levels of depersonalization. Using a sequential matching task, we compared three types of biases for processing of self-related information: prioritization of one’s name, of self-associated abstract stimuli (geometrical shapes), and of self-associated bodily stimuli (avatar faces). We found that both groups demonstrated the standard pattern of results for self-prioritization of one’s name and geometrical shapes, but they differed with regard to avatar faces. While people with low depersonalization showed the standard prioritization of avatar faces, people with high depersonalization showed overall better response accuracy with avatar faces, and faster response times for stranger-associated avatar faces. These results were complemented by the additional finding that people with high depersonalization reported being more likely to use avatars of a different gender to their own outside of the experimental context. Finally, in this large sample (N = 180) we investigated the relationships between different measures of self-related processing and self-identification, finding no correlation between explicit reports of self-identification with self-associated avatar faces and geometrical shapes, self-prioritization of these stimuli, and prioritization of one’s name.

The cultural transmission of technical know-how has proven vital to the success of our species. The broad diversity of learning contexts and social configurations, as well as the various kinds of coordinated interactions they involve, speaks to our capacity to flexibly adapt to and succeed in transmitting vital knowledge in various learning contexts. Although often recognized by ethnographers, the flexibility of cultural learning has so far received little attention in terms of cognitive mechanisms. We argue that a key feature of the flexibility of cultural learning is that both the models and learners recruit cognitive mechanisms of action coordination to modulate their behavior contingently on the behavior of their partner, generating a process of mutual adaptation supporting the successful transmission of technical skills in diverse and fluctuating learning environments. We propose that the study of cultural learning would benefit from the experimental methods, results, and insights of joint-action research and, complementarily, that the field of joint-action research could expand its scope by integrating a learning and cultural dimension. Bringing these two fields of research together promises to enrich our understanding of cultural learning, its contextual flexibility, and joint action coordination.

Prudently choosing who to interact with and who to avoid is an important ability to ensure that we benefit from a cooperative interaction. While the role of others' preferences, attributes, and values in partner choice have been established (Rossetti, Hilbe & Hauser, 2022), much less is known about whether the manner in which a potential partner plans and implements a decision provides helpful cues for partner choice. We used a partner choice paradigm in which participants chose who to partner with in economic games (either prisoners’ dilemma or stag-hunt). Before making their choice between two partners, participants were presented with information about the potential partners’ decision-related actions in another round of that same game. They received either information about the potential partners’ planning during decision making (Experiment 1, N = 144) or action execution during decision implementation (Experiment 2, N = 144). Across both games, participants preferred to interact with those whose action planning or action execution indicated they were making and implementing prosocial decisions (i.e., cooperate or stag) with certainty. This demonstrates that action cues present in either the planning or implementation of economic decisions influence partner choice, by revealing the strength of the social preferences of potential partners. We discuss implications of this finding for human decision-making and perception-action coupling in action understanding.

Previous research has shown that a co-actor's willingness to bear the monetary costs of prior cooperative activities influences our cooperative behaviour towards them. But what about when such information is lacking? In addition to monetary costs, people routinely engage in joint actions in which they incur effort costs in order to help each other achieve their goals, for example by adapting their goal-directed actions in order to send informative signals. We aimed to investigate whether people act more cooperatively towards those who are willing to bear the effort costs of an interaction by adapting their movements to send informative signals. We find that the effort that a co-actor invests in order to produce informative movement adaptations increases a participant's trust towards that co-actor, and that both the effort and utility of these informative movement adaptations increase generosity towards that co-actor. This demonstrates that we may base decisions about cooperation with a person on their willingness to bear the effort costs of interaction. These findings are discussed with respect to the role that effort investment plays in sustained cooperation.

Depersonalization is a common and distressing experience characterized by a feeling of estrangement from one’s self, body and the world. In order to examine the relationship between depersonalization and selfhood we conducted an experimental study comparing processing of three types of self-related information between non-clinical groups of people experiencing high and low levels of depersonalization. Using a sequential matching task, we compared three types of biases for processing of self-related information: prioritization of one’s name, of self-associated abstract stimuli (geometrical shapes), and of self-associated bodily stimuli (avatar faces). We found that both groups demonstrated the standard pattern of results for self-prioritization of one’s name and geometrical shapes, but they differed with regards to avatar faces. While people with low depersonalization showed the standard prioritization of avatar faces, people with high depersonalization showed overall better response accuracy with avatar faces, and faster response times for stranger-associated avatar faces. These results were complemented by the additional finding that people with high depersonalization reported being more likely to use avatars of a different gender to their own outside of the experimental context. Finally, in this large sample (N=180) we investigated the relationships between different measures of self-related processing and self-identification, finding no correlation between explicit reports of self-identification with self-associated avatar faces and geometrical shapes, self-prioritization of these stimuli, and prioritization of one’s name.

We tested the hypothesis that, if a robot apparently invests effort in teaching a new skill to a human participant, the human participant will reciprocate by investing more effort in teaching the robot a new skill, too. To this end, we devised a scenario in which the iCub and a human participant alternated in teaching each other new skills. In the Adaptive condition of the robot teaching phase , the iCub slowed down its movements when repeating a demonstration for the human learner, whereas in the Unadaptive condition it sped the movements up when repeating the demonstration. In a subsequent participant teaching phase , human participants were asked to give the iCub a demonstration, and then to repeat it if the iCub had not understood. We predicted that in the Adaptive condition , participants would reciprocate the iCub’s adaptivity by investing more effort to slow down their movements and to increase segmentation when repeating their demonstration. The results showed that this was true when participants experienced the Adaptive condition after the Unadaptive condition and not when the order was inverted, indicating that participants were particularly sensitive to the changes in the iCub’s level of commitment over the course of the experiment.