Bumblebees socially learn behaviour too complex to innovate alone.

Culture refers to behaviours that are socially learned and persist within a population over time. Increasing evidence suggests that animal culture can, like human culture, be cumulative: characterized by sequential innovations that build on previous ones1. However, human cumulative culture involves behaviours so complex that they lie beyond the capacity of any individual to independently discover during their lifetime1-3. To our knowledge, no study has so far demonstrated this phenomenon in an invertebrate. Here we show that bumblebees can learn from trained demonstrator bees to open a novel two-step puzzle box to obtain food rewards, even though they fail to do so independently. Experimenters were unable to train demonstrator bees to perform the unrewarded first step without providing a temporary reward linked to this action, which was removed during later stages of training. However, a third of naive observer bees learned to open the two-step box from these demonstrators, without ever being rewarded after the first step. This suggests that social learning might permit the acquisition of behaviours too complex to 're-innovate' through individual learning. Furthermore, naive bees failed to open the box despite extended exposure for up to 24 days. This finding challenges a common opinion in the field: that the capacity to socially learn behaviours that cannot be innovated through individual trial and error is unique to humans.

Language is primarily a tool for communication rather than thought.

Language is a defining characteristic of our species, but the function, or functions, that it serves has been debated for centuries. Here we bring recent evidence from neuroscience and allied disciplines to argue that in modern humans, language is a tool for communication, contrary to a prominent view that we use language for thinking. We begin by introducing the brain network that supports linguistic ability in humans. We then review evidence for a double dissociation between language and thought, and discuss several properties of language that suggest that it is optimized for communication. We conclude that although the emergence of language has unquestionably transformed human culture, language does not appear to be a prerequisite for complex thought, including symbolic thought. Instead, language is a powerful tool for the transmission of cultural knowledge; it plausibly co-evolved with our thinking and reasoning capacities, and only reflects, rather than gives rise to, the signature sophistication of human cognition.

100 ancient genomes show repeated population turnovers in Neolithic Denmark.

Major migration events in Holocene Eurasia have been characterized genetically at broad regional scales1-4. However, insights into the population dynamics in the contact zones are hampered by a lack of ancient genomic data sampled at high spatiotemporal resolution5-7. Here, to address this, we analysed shotgun-sequenced genomes from 100 skeletons spanning 7,300 years of the Mesolithic period, Neolithic period and Early Bronze Age in Denmark and integrated these with proxies for diet (13C and 15N content), mobility (87Sr/86Sr ratio) and vegetation cover (pollen). We observe that Danish Mesolithic individuals of the Maglemose, Kongemose and Ertebølle cultures form a distinct genetic cluster related to other Western European hunter-gatherers. Despite shifts in material culture they displayed genetic homogeneity from around 10,500 to 5,900 calibrated years before present, when Neolithic farmers with Anatolian-derived ancestry arrived. Although the Neolithic transition was delayed by more than a millennium relative to Central Europe, it was very abrupt and resulted in a population turnover with limited genetic contribution from local hunter-gatherers. The succeeding Neolithic population, associated with the Funnel Beaker culture, persisted for only about 1,000 years before immigrants with eastern Steppe-derived ancestry arrived. This second and equally rapid population replacement gave rise to the Single Grave culture with an ancestry profile more similar to present-day Danes. In our multiproxy dataset, these major demographic events are manifested as parallel shifts in genotype, phenotype, diet and land use.

Groundwater-dependent ecosystem map exposes global dryland protection needs.

Groundwater is the most ubiquitous source of liquid freshwater globally, yet its role in supporting diverse ecosystems is rarely acknowledged1,2. However, the location and extent of groundwater-dependent ecosystems (GDEs) are unknown in many geographies, and protection measures are lacking1,3. Here, we map GDEs at high-resolution (roughly 30 m) and find them present on more than one-third of global drylands analysed, including important global biodiversity hotspots4. GDEs are more extensive and contiguous in landscapes dominated by pastoralism with lower rates of groundwater depletion, suggesting that many GDEs are likely to have already been lost due to water and land use practices. Nevertheless, 53% of GDEs exist within regions showing declining groundwater trends, which highlights the urgent need to protect GDEs from the threat of groundwater depletion. However, we found that only 21% of GDEs exist on protected lands or in jurisdictions with sustainable groundwater management policies, invoking a call to action to protect these vital ecosystems. Furthermore, we examine the linkage of GDEs with cultural and socio-economic factors in the Greater Sahel region, where GDEs play an essential role in supporting biodiversity and rural livelihoods, to explore other means for protection of GDEs in politically unstable regions. Our GDE map provides critical information for prioritizing and developing policies and protection mechanisms across various local, regional or international scales to safeguard these important ecosystems and the societies dependent on them.

A leadership-level culture cycle intervention changes teachers' culturally inclusive beliefs and practices.

Despite an abundance of support for culturally inclusive learning environments, there is little consensus regarding how to change educational contexts to effectively and sustainably foster cultural inclusion. To address this gap, we report findings from a research-practice partnership that leveraged the Culture Cycle Framework (CCF) to expand educators' praxis to include both independent and interdependent models of self. Most U.S. schools validate independent cultural models (i.e., those that prioritize individuality, uniqueness, and personal agency) and overlook interdependent models (i.e., those that prioritize connectedness, relationality, and collective well-being), which are more common among students from marginalized racial and socioeconomic backgrounds. Using a quasi-experimental longitudinal design, we trained school leadership to integrate ideas about cultural inclusion (i.e., validating the importance of both independent and interdependent cultural models) into school-wide flagship practices. We assessed downstream indicators of culture change by surveying teachers and students across the district and found that a) leadership-level training enhanced school-wide beliefs about cultural inclusion, b) teachers' endorsement of culturally inclusive beliefs predicted their use of culturally inclusive practices, and c) teachers' use of culturally inclusive practices predicted enhanced psychosocial and academic outcomes among students. This research represents a comprehensive culture change effort using the CCF and illustrates a means of fostering inclusion-focused educational culture change and assessing downstream consequences of culture change initiatives.

Formation of human kinship structures depending on population size and cultural mutation rate.

How does social complexity depend on population size and cultural transmission? Kinship structures in traditional societies provide a fundamental illustration, where cultural rules between clans determine people's marriage possibilities. Here, we propose a simple model of kinship interactions that considers kin and in-law cooperation and sexual rivalry. In this model, multiple societies compete. Societies consist of multiple families with different cultural traits and mating preferences. These values determine interactions and hence the growth rate of families and are transmitted to offspring with mutations. Through a multilevel evolutionary simulation, family traits and preferences are grouped into multiple clans with interclan mating preferences. It illustrates the emergence of kinship structures as the spontaneous formation of interdependent cultural associations. Emergent kinship structures are characterized by the cycle length of marriage exchange and the number of cycles in society. We numerically and analytically clarify their parameter dependence. The relative importance of cooperation versus rivalry determines whether attraction or repulsion exists between families. Different structures evolve as locally stable attractors. The probabilities of formation and collapse of complex structures depend on the number of families and the mutation rate, showing characteristic scaling relationships. It is now possible to explore macroscopic kinship structures based on microscopic interactions, together with their environmental dependence and the historical causality of their evolution. We propose the basic causal mechanism of the formation of typical human social structures by referring to ethnographic observations and concepts from statistical physics and multilevel evolution. Such interdisciplinary collaboration will unveil universal features in human societies.

Arranged cohabitation among Chinese Muslims.

While modern family-related ideas and behaviors have become more widely accepted in contemporary China, Chinese Muslim minorities continue to hold on to traditional religious practices. Surprisingly, data from our survey conducted in Gansu province in China's northwestern borderlands reveal that Muslims of the Hui and Dongxiang ethnicities reported much higher rates of cohabitation experience than the secular majority Han. Based on follow-up qualitative interviews, we found the answer to lie in the interplay between the highly interventionist Chinese state and the robust cultural resilience of local Islamic communities. While the state maintains a high minimum legal age of marriage, the early marriage norm remains strong in Chinese Muslim communities, where religion constitutes an alternative and often more powerful source of legitimacy-at least in the private sphere of life. Using the 2000 census data, we further show that women in almost all 10 Muslim ethnic groups have higher percentages of underage births and premarital births than Han women, both nationally and in the northwest where most Chinese Muslims live. As the once-outlawed behavior of cohabitation became more socially acceptable during the reform and opening-up era, young Muslim Chinese often found themselves in "arranged cohabitations" as de facto marriages formed at younger-than-legal ages. In doing so, Chinese Muslim communities have reinvented the meaning of cohabitation. Rather than liberal intimate relationship based on individual autonomy, cohabitation has served as a coping strategy by which Islamic patriarchs circumvent the Chinese state's aggressive regulations aimed at "modernizing" the Muslim family.

Belief Updating during Social Interactions: Neural Dynamics and Causal Role of Dorsomedial Prefrontal Cortex.

In competitive interactions, humans have to flexibly update their beliefs about another person's intentions in order to adjust their own choice strategy, such as when believing that the other may exploit their cooperativeness. Here we investigate both the neural dynamics and the causal neural substrate of belief updating processes in humans. We used an adapted prisoner's dilemma game in which participants explicitly predicted the coplayer's actions, which allowed us to quantify the prediction error between expected and actual behavior. First, in an EEG experiment, we found a stronger medial frontal negativity (MFN) for negative than positive prediction errors, suggesting that this medial frontal ERP component may encode unexpected defection of the coplayer. The MFN also predicted subsequent belief updating after negative prediction errors. In a second experiment, we used transcranial magnetic stimulation (TMS) to investigate whether the dorsomedial prefrontal cortex (dmPFC) causally implements belief updating after unexpected outcomes. Our results show that dmPFC TMS impaired belief updating and strategic behavioral adjustments after negative prediction errors. Taken together, our findings reveal the time course of the use of prediction errors in social decisions and suggest that the dmPFC plays a crucial role in updating mental representations of others' intentions.

Beliefs, compulsive behavior and reduced confidence in control.

OCD has been conceptualized as a disorder arising from dysfunctional beliefs, such as overestimating threats or pathological doubts. Yet, how these beliefs lead to compulsions and obsessions remains unclear. Here, we develop a computational model to examine the specific beliefs that trigger and sustain compulsive behavior in a simple symptom-provoking scenario. Our results demonstrate that a single belief disturbance-a lack of confidence in the effectiveness of one's preventive (harm-avoiding) actions-can trigger and maintain compulsions and is directly linked to compulsion severity. This distrust can further explain a number of seemingly unrelated phenomena in OCD, including the role of not-just-right feelings, the link to intolerance to uncertainty, perfectionism, and overestimation of threat, and deficits in reversal and state learning. Our simulations shed new light on which underlying beliefs drive compulsive behavior and highlight the important role of perceived ability to exert control for OCD.

Different learning aberrations relate to delusion-like beliefs with different contents.

The prediction error account of delusions has had success. However, its explanation of delusions with different contents has been lacking. Persecutory delusions and paranoia are the common unfounded beliefs that others have harmful intentions towards us. Other delusions include believing that one's thoughts or actions are under external control or that events in the world have specific personal meaning. We compare learning in two different cognitive tasks, probabilistic reversal learning and Kamin blocking, that have relationships to paranoid and non-paranoid delusion-like beliefs, respectively. We find that clinical high-risk status alone does not result in different behavioural results in the probabilistic reversal learning task but that an individual's level of paranoia is associated with excessive switching behaviour. During the Kamin blocking task, paranoid individuals learned inappropriately about the blocked cue. However, they also had decreased learning about the control cue, suggesting more general learning impairments. Non-paranoid delusion-like belief conviction (but not paranoia) was associated with aberrant learning about the blocked cue but intact learning about the control cue, suggesting specific impairments in learning related to cue combination. We fit task-specific computational models separately to behavioural data to explore how latent parameters vary within individuals between tasks and how they can explain symptom-specific effects. We find that paranoia is associated with low learning rates in the probabilistic reversal learning task and the blocking task. Non-paranoid delusion-like belief conviction is instead related to parameters controlling the degree and direction of similarity between cue updating during simultaneous cue presentation. These results suggest that paranoia and other delusion-like beliefs involve dissociable deficits in learning and belief updating, which, given the transdiagnostic status of paranoia, might have differential utility in predicting psychosis.

Phase synchronization between culture and climate forcing.

Over the history of humankind, cultural innovations have helped improve survival and adaptation to environmental stress. This has led to an overall increase in human population size, which in turn further contributed to cumulative cultural learning. During the Anthropocene, or arguably even earlier, this positive sociodemographic feedback has caused a strong decline in important resources that, coupled with projected future transgression of planetary boundaries, may potentially reverse the long-term trend in population growth. Here, we present a simple consumer/resource model that captures the coupled dynamics of stochastic cultural learning and transmission, population growth and resource depletion in a changing environment. The idealized stochastic mathematical model simulates boom/bust cycles between low-population subsistence, high-density resource exploitation and subsequent population decline. For slow resource recovery time scales and in the absence of climate forcing, the model predicts a long-term global population collapse. Including a simplified periodic climate forcing, we find that cultural innovation and population growth can couple with climatic forcing via nonlinear phase synchronization. We discuss the relevance of this finding in the context of cultural innovation, the anthropological record and long-term future resilience of our own predatory species.

Blending Indigenous and western science: Quantifying cultural burning impacts in Karuk Aboriginal Territory.

The combined effects of Indigenous fire stewardship and lightning ignitions shaped historical fire regimes, landscape patterns, and available resources in many ecosystems globally. The resulting fire regimes created complex fire-vegetation dynamics that were further influenced by biophysical setting, disturbance history, and climate. While there is increasing recognition of Indigenous fire stewardship among western scientists and managers, the extent and purpose of cultural burning is generally absent from the landscape-fire modeling literature and our understanding of ecosystem processes and development. In collaboration with the Karuk Tribe Department of Natural Resources, we developed a transdisciplinary Monte Carlo simulation model of cultural ignition location, frequency, and timing to simulate spatially explicit cultural ignitions across a 264,399-ha landscape within Karuk Aboriginal Territory in northern California. Estimates of cultural ignition parameters were developed with Tribal members and knowledge holders using existing interviews, historical maps, ethnographies, recent ecological studies, contemporary maps, and generational knowledge. Spatial and temporal attributes of cultural burning were explicitly tied to the ecology of specific cultural resources, fuel receptivity, seasonal movement patterns, and spiritual practices. Prior to colonization, cultural burning practices were extensive across the study landscape with an estimated 6972 annual ignitions, averaging approximately 6.5 ignitions per Indigenous fire steward per year. The ignition characteristics we document align closely with data on historical fire regimes and vegetation but differ substantially from the location and timing of contemporary ignitions. This work demonstrates the importance of cultural burning for developing and maintaining the ecosystems present at the time of colonization and underscores the need to work collaboratively with Indigenous communities to restore ecocultural processes in these systems.

The truth is in there: Belief processes in the human brain.

Belief, defined by William James as the mental state or function of cognizing reality, is a core psychological function with strong influence on emotion and behavior. Furthermore, strong and aberrant beliefs about the world and oneself play important roles in mental disorders. The underlying processes of belief have been the matter of a long debate in philosophy and psychology, and modern neuroimaging techniques can provide insight into the underlying neural processes. Here, we conducted a functional magnetic resonance imaging study with N = 30 healthy participants in which we presented statements about facts, politics, religion, conspiracy theories, and superstition. Participants judged whether they considered them as true (belief) or not (disbelief) and reported their certainty in the decision. We found belief-associated activations in bilateral dorsolateral prefrontal cortex, left superior parietal cortex, and left lateral frontopolar cortex. Disbelief-associated activations were found in an anterior temporal cluster extending into the amygdala. We found a larger deactivation for disbelief than belief in the ventromedial prefrontal cortex that was most pronounced during decisions, suggesting a role of the vmPFC in belief-related decision-making. As a category-specific effect, we found disbelief-associated activation in retrosplenial cortex and parahippocampal gyrus for conspiracy theory statements. Exploratory analyses identified networks centered at anterior cingulate cortex for certainty, and dorsomedial prefrontal cortex for uncertainty. The uncertainty effect identifies a neural substrate for Alexander Bain's notion from 1859 of uncertainty as the real opposite of belief. Taken together, our results suggest a two-factor neural process model of belief with falsehood/veracity and uncertainty/certainty factors.

Beliefs about social mobility in young American children.

Although actual experiences of upward social mobility are historically low, many adolescents and adults express a belief in social mobility (e.g., that social status can change). Although a belief in upward mobility (e.g., that status can improve) can be helpful for economically disadvantaged adolescents and adults, a belief in upward social mobility in adults is also associated with greater acceptance of societal inequality. While this belief might have similar benefits or consequences in children, no previous work has examined whether children are even capable of reasoning about social mobility. This is surprising, given that elementary-aged children exhibit sophisticated reasoning about both social status, as well as about the fixedness or malleability of properties and group membership. Across an economically advantaged group of 5- to 12-year-old American children (N = 151, Mage = 8.91, 63% racial majority, 25% racially marginalized; Mhousehold income = $133,064), we found evidence that children can reason about social mobility for their own families and for others. Similar to research in adults, children believe that others are more likely to experience upward than downward mobility. However, in contrast to adult's typical beliefs-but in line with economic realities-between 7- and 9-years-old, children become less likely to expect upward mobility for economically disadvantaged, versus advantaged, families. In sum, children are capable of reasoning about social mobility in nuanced ways; future work should explore the implications of these beliefs. RESEARCH HIGHLIGHTS: Despite harsh economic realities, a belief in upward social mobility and the American Dream is alive and well. Between 7 and 9 years of age, economically advantaged, American children begin to expect economically disadvantaged families to experience less upward mobility than economically advantaged families. Children's beliefs about social mobility better accord with reality than adults' do.

Socio-cultural beliefs and perceptions influencing diagnosis and treatment of breast cancer among women in Ghana: a systematic review.

BACKGROUND: Breast cancer is currently the most commonly diagnosed cancer in Ghana and the leading cause of cancer mortality among women. Few published empirical evidence exist on cultural beliefs and perceptions about breast cancer diagnosis and treatment in Ghana. This systematic review sought to map evidence on the socio-cultural beliefs and perceptions influencing the diagnosis and treatment of breast cancer among Ghanaian women. METHODS: This review was conducted following the methodological guideline of Joanna Briggs Institute and reported in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses. The literature search was conducted in PubMed, CINAHL via EBSCOhost, PsycINFO, Web of Science, and Embase. Studies that were conducted on cultural, religious, and spiritual beliefs were included. The included studies were screened by title, abstract, and full text by three reviewers. Data were charted and results were presented in a narrative synthesis form. RESULTS: After the title, abstract, and full-text screening, 15 studies were included. Three categories were identified after the synthesis of the charted data. The categories included: cultural, religious and spiritual beliefs and misconceptions about breast cancer. The cultural beliefs included ancestral punishment and curses from the gods for wrongdoing leading to breast cancer. Spiritual beliefs about breast cancer were attributed to spiritual or supernatural forces. People had the religious belief that breast cancer is a test from God and they resorted to prayers for healing. Some women perceived that breast cancer is caused by spider bites, heredity, extreme stress, trauma, infections, diet, or lifestyle. CONCLUSION: This study adduces evidence of the socio-cultural beliefs that impact on the diagnosis and treatment of breast cancer among women in Ghana. Taking into consideration the diverse cultural and traditional beliefs about breast cancer diagnosis and treatment, there is a compelling need to intensify nationwide public education on breast cancer to clarify the myths and misconceptions about the disease. We recommend the need to incorporate socio-cultural factors influencing breast cancer diagnosis and treatment into breast cancer awareness programs, education, and interventions in Ghana.

Three- and 5-year-old children know their current belief might be wrong.

By 4 or 5 years of age, children understand when their own past beliefs were incorrect, or when others' current beliefs are incorrect. In the current study, we asked whether young children understand when their own current belief might be incorrect. 3- and 5-year old children (N = 77) made a judgment and then experienced a puppet making a judgment about the same situation. Children of both ages rechecked their evidence more often when the puppet disagreed with them than when it agreed with them (and the nature of their rechecking was different in the two conditions as well). These results suggest that already by 3 years of age children understand that they might currently be wrong, and they know that rechecking the evidence can resolve their uncertainty.

Children's animistic beliefs toward a humanoid robot and other objects.

This study examined children's beliefs about a humanoid robot by examining their behavioral and verbal responses. We investigated whether 3- and 5-year-old children would treat the humanoid robot gently along with other objects and tools with and without a face and whether 3- and 5-year-olds would attribute moral, perceptual, and psychological properties to these targets. Although 3-year-olds did not treat objects gently or rudely, they were likely to affirm that hitting targets was acceptable despite targets having psychological and perceptual properties. Thus, 3-year-olds' perception of the targets was incongruent with their behavior toward them. Most 5-year-olds treated a robot gently and were likely to affirm the robot's psychological characteristics. Behaviors and perceptions of the robot differed between 3- and 5-year-olds. Thus, children may start believing that robots are not alive at age five, and they can distinguish them from other objects even when the latter have faces. Developmental changes in children's animistic beliefs are also discussed.

Pathways between foodways and wellbeing for first nations Australians.

BACKGROUND: Supporting the health and wellbeing of Aboriginal and Torres Strait Islander peoples (hereafter respectfully referred to as First Nations peoples) is a national priority for Australia. Despite immense losses of land, language, and governance caused by the continuing impact of colonisation, First Nations peoples have maintained strong connections with traditional food culture, while also creating new beliefs, preferences, and traditions around food, which together are termed foodways. While foodways are known to support holistic health and wellbeing for First Nations peoples, the pathways via which this occurs have received limited attention. METHODS: Secondary data analysis was conducted on two national qualitative datasets exploring wellbeing, which together included the views of 531 First Nations peoples (aged 12-92). Thematic analysis, guided by an Indigenist research methodology, was conducted to identify the pathways through which foodways impact on and support wellbeing for First Nations peoples. RESULTS AND CONCLUSIONS: Five pathways through which wellbeing is supported via foodways for First Nations peoples were identified as: connecting with others through food; accessing traditional foods; experiencing joy in making and sharing food; sharing information about food and nutrition; and strategies for improving food security. These findings offer constructive, nationally relevant evidence to guide and inform health and nutrition programs and services to harness the strengths and preferences of First Nations peoples to support the health and wellbeing of First Nations peoples more effectively.

'Doing culture' in contemporary south-eastern Australia: how Indigenous people are creating and maintaining strong cultural identities for improved health and wellbeing.

BACKGROUND: Indigenous people in Australia experience far poorer health than non-Indigenous Australians. A growing body of research suggests that Indigenous people who are strong in their cultural identity experience better health than those who are not. Yet little is known about how Indigenous people create and maintain strong cultural identities in the contemporary context. This paper explores how Indigenous people in south-eastern Australia create and maintain strong cultural identities to support their health and wellbeing. METHODS: Data were collected from 44 Indigenous people living in the south-eastern Australian state of Victoria via yarning. Yarning is a cultural mode of conversation that privileges Indigenous ways of knowing, doing and being. Yarning participants were selected for their prominence within Victorian Indigenous health services and/or their prominence within the Victorian Indigenous community services sector more broadly. Due to the restrictions of COVID-19, yarns were conducted individually online via Zoom. Data were analysed employing constructivist grounded theory, which was the overarching qualitative research methodology. RESULTS: All yarning participants considered maintaining a strong cultural identity as vital to maintaining their health and wellbeing. They did this via four main ways: knowing one's Mob and knowing one's Country; connecting with one's own Mob and with one's own Country; connecting with Community and Country more broadly; and connecting with the more creative and/or expressive elements of Culture. Importantly, these practices are listed in order of priority. Indigenous people who either do not know their Mob or Country, or for whom the connections with their own Mob and their own Country are weak, may therefore be most vulnerable. This includes Stolen Generations survivors, their descendants, and others impacted by historical and contemporary child removal practices. CONCLUSIONS: The yarns reveal some of the myriad practical ways that Indigenous people maintain a strong cultural identity in contemporary south-eastern Australia. While programs designed to foster connections to Community, Country and/or Culture may benefit all Indigenous participants, those most disconnected from their Ancestral roots may benefit most. Further research is required to determine how best to support Indigenous Victorians whose connections to their own Mob and their own Country are unable to be (re)built.