Determining when to switch from one strategy to another is at the heart of adaptive decision-making. Previous research shows that humans exhibit a ‘cognitive set’ bias, which occurs when a familiar strategy occludes—even much better—alternatives. Here we examined the mechanisms underlying cognitive set by investigating whether better solutions are visually overlooked, or fixated on but disregarded. We analyzed gaze data from 67 American undergraduates (91% female) while they completed the learned strategy-direct strategy (LS-DS) task, which measures their ability to switch from a learned strategy (LS) to a more efficient direct strategy (DS or shortcut). We found that, in the first trial block, participants fixated on the location of the shortcut more when it was available but most (89.6%) did not adopt it. Next, participants watched a video demonstrating either the DS (N = 34 Informed participants) or the familiar LS (N = 33 Controls). In post-video trials, Informed participants used the DS more than pre-video trials and compared to Controls. Notably, 29.4% of Informed participants continued to use the LS despite watching the DS video. We suggest that cognitive set in the LS-DS task does not stem from an inability to see the shortcut but rather a failure to try it.

Compared to other species, the extent of human cooperation is unparalleled. Such cooperation is coordinated between community members via social norms. Developmental research has demonstrated that very young children are sensitive to social norms, and that social norms are internalized by middle childhood. Most research on social norm acquisition has focused on norms that modulated intra-group cooperation. Yet around the world, multi-ethnic communities also cooperate, and this cooperation is often shaped by distinct inter-group social norms. In the present study, we will investigate whether inter-ethnic and intra-ethnic social norm acquisition follows the same, or distinct, developmental trajectories. Specifically, we will work with BaYaka foragers and Bandongo fisher-farmers who inhabit multi-ethnic villages in the Republic of the Congo. In these villages, inter-ethnic cooperation is regulated by sharing norms. Through interviews with adult participants, we will provide the first descriptive account of the timing and mechanism by which BaYaka and Bandongo learn to share with out-group members. Children (5–17 years) and adults (17+ years) will also participate in a modified Dictator Game to investigate the developmental trajectories of children’s intra- and inter-ethnic sharing choices. Based on our ethnographic knowledge of the participating communities, we predict that children’s intra-ethnic sharing choices in the Dictator Game will match those of adults at an earlier age than their inter-ethnic sharing choices. We will analyze our data using logistic Bayesian modelling.

In this article, we integrate cultural evolutionary theory with empirical research from developmental psychology, cultural anthropology, and primatology to explore the role of peer learning in the development of complex instrumental skills and behavioral norms. We show that instrumental imitation, contingent teaching, generative collaboration, and selective copying contribute to domain‐specific transmission of knowledge between peers. Stages of development and characteristics inherent to the learner and model influence how and when children learn from each other. Peer learning is persistent across societies despite cultural beliefs that favor adult–child transmission in some settings. Comparative research hints at the possibility that children's greater motivation to interact with and learn from each other may set humans apart from other primates. We conclude by outlining avenues for future research, including how individual characteristics and developmental changes in social networks, motivation, and cognition may contribute to cultural evolution.

Human cognition is incredibly flexible, allowing us to thrive within diverse environments. However, humans also tend to stick to familiar strategies, even when there are better solutions available. How do we exhibit flexibility in some contexts, yet inflexibility in others? The Constrained Flexibility Framework (CFF) proposes that cognitive flexibility is shaped by variability, predictability, and harshness within decision-making environments. The CFF asserts that high elective flexibility (switching away from a working strategy) is maladaptive in stable or predictably variable environments, but adaptive in unpredictable environments, so long as harshness is low. Here we provide evidence for the CFF using a decision-making task completed by 100 English-speaking adults. In line with the CFF, we found that elective flexibility was suppressed in Stable Not Harsh, Stable Harsh, and Variable Harsh conditions compared to the Variable Not Harsh condition. Our results highlight the need to study how cognitive flexibility adapts to diverse contexts.