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Humans can learn from observing diverse others, even when they know little about their exact preferences, skills, or goals. Yet, while our remarkable social learning abilities have been a popular research topic, prior work has generally been limited to tasks in which observer and demonstrator share the same value function.To address this discrepancy, we use the socially correlated bandit task, where participants explore positively correlated, rather than identical, environments in groups. We extend existing work using this paradigm by comparing behaviour across individual and social rounds within participants.We replicate findings that humans are able to use correlated social information effectively, with behaviour being best described by a model noisily integrates social information. In comparing individual and social search behaviour, we find that social learning partially replaces directed exploration. In conclusion, we find that humans use social information flexibly, employing it as an exploration tool, despite our differences.

Humans are remarkably effective social learners, with several recent studies formalizing this capacity using computational models. However, previous research has often been limited to tasks where observer and demonstrator share the same reward function. In contrast, humans can learn from others who have different preferences, skills, or goals. To study social learning under individual differences, we introduce the socially correlated bandit, where participants have personalized rewards, which are correlated with but not identical to those of others. Social information can still be useful, but not when used verbatim. We present a model of social generalization that integrates individual and social information into the generalization process, but assumes social information to be noisier and thus less informative. This model out-competes previous models, with it being the dominant strategy in evolutionary simulations. Our findings expand on previous models of social learning, showing humans can integrate social information more flexibly than previously assumed.

Social learning is common in nature, yet cumulative culture (where knowledge and technology increase in complexity and diversity over time) appears restricted to humans. To understand why, we organized a computer tournament in which programmed entries specified when to learn new knowledge and when to refine (i.e. improve) existing knowledge. The tournament revealed a 'refinement paradox': refined behavior afforded higher payoffs as individuals converged on a small number of successful behavioral variants, but refining did not generally pay. Paradoxically, entries that refined only in certain conditions did best during behavioral improvement, while simple copying entries thrived when refinement levels were high. Cumulative cultural evolution may be rare in part because sophisticated strategies for improving knowledge and technology are initially advantageous, yet complex culture, once achieved, favors conformity, blind imitation and hyper-credulity. Author summary: Although social learning, culture, and traditions are found in animals, why humans seem to be the only species that builds on knowledge and technology over generations is still not fully understood. Here we organized a computer tournament in which programmed entries specified when to learn new knowledge and when to refine (i.e. improve upon) existing knowledge. We found a 'refinement paradox': while using refined behavior was beneficial to individuals, it was not beneficial to be the one doing the refining. Entries that refined selectively, only under limited conditions, did well while refinement levels increased, but once refinement was high simple entries that did not refine thrived. This result might explain why cumulative culture is rare in nature: sophisticated strategies for improving knowledge are initially advantageous, but once complex culture is common it pays to conform to the behavior of others and copy blindly. [ABSTRACT FROM AUTHOR]

There has been much progress in understanding human social learning, including recent studies integrating social information into the reinforcement learning framework. Yet previous studies often assume identical payoffs between observer and demonstrator, overlooking the diversity of social information in real-world interactions. We address this gap by introducing a socially correlated bandit task that accommodates payoff differences among participants, allowing for the study of social learning under more realistic conditions. Our Social Generalization (SG) model, tested through evolutionary simulations and two online experiments, outperforms existing models by incorporating social information into the generalization process, but treating it as noisier than individual observations. Our findings suggest that human social learning is more flexible than previously believed, with the SG model indicating a potential resourcerational trade-off where social learning partially replaces individual exploration. This research highlights the flexibility of humans' social learning, allowing us to integrate social information from others with different preferences, skills, or goals. [ABSTRACT FROM AUTHOR]

As humans increasingly modify the natural world, many animals have responded by changing their behaviour. Understanding and predicting the extent of these responses is a key step in conserving these species. For example, the tendency for some species of birds to incorporate anthropogenic items—particularly plastic material—into their nests is of increasing concern, as in some cases, this behaviour has harmful effects on adults, young and eggs. Studies of this phenomenon, however, have to date been largely limited in geographic and taxonomic scope. To investigate the global correlates of anthropogenic (including plastic) nest material use, we used Bayesian phylogenetic mixed models and a data set of recorded nest materials in 6147 species of birds. We find that, after controlling for research effort and proximity to human landscape modifications, anthropogenic nest material use is correlated with synanthropic (artificial) nesting locations, breeding environment and the number of different nest materials the species has been recorded to use. We also demonstrate that body mass, range size, conservation status and brain size do not explain variation in the recorded use of anthropogenic nest materials. These results indicate that anthropogenic materials are more likely to be included in nests when they are more readily available, as well as potentially by species that are more flexible in their nest material choice. [ABSTRACT FROM AUTHOR]

Motivation: A well‐constructed nest is a key element of successful reproduction in most species of birds, and nest morphology varies widely across the class. Macroecological and macroevolutionary studies tend to group nest design into a small number of discrete categories, often based on taxonomic inference. In reality, however, many species display considerable intraspecific variation in their nest‐building behaviour, and broad‐level categories may include several functionally distinct nest types. To address this imprecision in the literature and facilitate future studies of broad‐scale variation in avian parental care, we here introduce a detailed, global comparative database of nest building in birds, together with preliminary correlations between these traits and species‐level environmental variables. Main types of variables contained: We present species‐level data for nest structure, location, height, material composition, sex of builder, building time and nest dimensions. Spatial location and grain: Global. Maps are presented at the 10 × 10 level. Time period and grain: Included species are generally extant, although we present some data for recently extinct taxa. The data were collected in 2017–2021 and was drawn from secondary sources published in 1992–2021. Major taxa and level of measurement: Partial or complete trait data is presented for 8601 species of birds, representing 36 of 36 orders and 239 of 243 families. Software format: Data have been uploaded as Supplementary Material in.csv format and are separated by species and source for all traits (Dataset S1, and Metadata) as well as summarized at the species level for the major structure and location variables (Dataset S2, and Metadata). [ABSTRACT FROM AUTHOR]

Evolvability refers to the capacity, ability, or potential of an organism to generate heritable variation. Under this view, much extragenetic inheritance is regarded not as noise, fine-tuning, or a luxury add-on to genetic inheritance but as an essential tool for short-term adaptation. With respect to humans, the cultural contribution to evolvability is key to understanding evolution. In many instances, cultural inheritance directs genetic inheritance, not the other way around. Culture, being relatively free from the genetic leash, can produce change that genetic inheritance cannot. Soft inheritance—the view that heredity can be changed by an organism's experiences—has been disdained for over a century, but in light of the recent outpouring of data demonstrating extragenetic inheritance, defining evolution only in terms of genetic change ignores half the adaptive process, discarding much of what is interesting and relevant. Archaeologists can play a key role in evolvability research, given their contributions to topics such as niche construction, modularity, mosaic evolution, and developmental bias. [ABSTRACT FROM AUTHOR]

Brood (social) parasites and their hosts exhibit a wide range of adaptations and counter-adaptations as part of their ongoing coevolutionary arms races. Obligate avian brood parasites are expected to use potential host species with more easily accessible nests, while potential hosts are expected to evade parasitism by building more concealed nests that are difficult for parasites to enter and in which to lay eggs. We used phylogenetically informed comparative analyses, a global database of the world's brood parasites, their host species, and the design of avian host and non-host nests (approx. 6200 bird species) to examine first, whether parasites preferentially target host species that build open nests and, second, whether host species that build enclosed nests are more likely to be targeted by specialist parasites. We found that species building more accessible nests are more likely to serve as hosts, while host species with some of the more inaccessible nests are targeted by more specialist brood parasites. Furthermore, evolutionary-transition analyses demonstrate that host species building enclosed nests frequently evolve to become non-hosts. We conclude that nest architecture and the accessibility of nests for parasitism represent a critical stage of the ongoing coevolutionary arms race between avian brood parasites and their hosts.