Reliable long-term individual variation in wild chimpanzee technological efficiency.

Variation in the efficiency of extracting calorie-rich and nutrient-dense resources directly impacts energy expenditure and potentially has important repercussions for cultural transmission where social learning strategies are used. Assessing variation in efficiency is key to understanding the evolution of complex behavioural traits in primates. Here we examine evidence for individual-level differences beyond age- and sex-class in non-human primate extractive foraging efficiency.

Psychological significance of name changes: A case study of (north) Macedonia's name referendum.

Multiple instances of rebranding of corporations or sports teams, or changes of personal names suggest that imposed change of symbols that people identify with leads to resistance towards the symbol change. In this paper, we examine the predictive role of sacred values, identity fusion, identification and essentialism in explaining such resistance, in a unique political context of a national referendum to change Macedonia to North Macedonia. Participants (ethnic Macedonians, N = 301) took a survey measuring these variables, along with their voting intentions and behaviour, 1 week prior to a national referendum on the name change, and again several weeks later.

Nonadjacent dependencies and sequential structure of chimpanzee action during a natural tool-use task.

Many of the complex behaviours of humans involve the production of nonadjacent dependencies between sequence elements, which in part can be generated through the hierarchical organization of sequences. To understand how these structural properties of human behaviours evolved, we can gain valuable insight from studying the sequential behaviours of nonhuman animals. Among the behaviours of nonhuman apes, tool use has been hypothesised to be a domain of behaviour which likely involves hierarchical organization, and may therefore possess nonadjacent dependencies between sequential actions.

Hominin brain size increase has emerged from within-species encephalization.

The fact that rapid brain size increase was clearly a key aspect of human evolution has prompted many studies focusing on this phenomenon, and many suggestions as to the underlying evolutionary patterns and processes. No study to date has however separated out the contributions of change through time within vs. between hominin species while simultaneously incorporating effects of body size.

Modern African ecosystems as landscape-scale analogues for reconstructing woody cover and early hominin environments.

Reconstructing habitat types available to hominins and inferring how the paleo-landscape changed through time are critical steps in testing hypotheses about the selective pressures that drove the emergence of bipedalism, tool use, a change in diet, and progressive encephalization. Change in the amount and distribution of woody vegetation has been suggested as one of the important factors that shaped early hominin evolution. Previous models for reconstructing woody cover at eastern African hominin fossil sites used global-scale modern soil comparative datasets.

Peer counseling for perinatal depression in low- and middle-income countries: A scoping review.

Perinatal depression is associated with adverse maternal, newborn and child health outcomes. Treatment gaps and sociocultural factors contribute to its disproportionate burden in low- and middle-income countries (LMICs). Task-sharing approaches, such as peer counseling, have been developed to improve access to mental health services.

Low haemoglobin in arduous seasons is associated with reduced chance of ovulation among women living in the Bolivian .

Background And Objectives: Female reproductive function flexibly responds to ecological variation in energy availability, but the roles of other ecologically limited resources, such as iron, remain poorly understood. This analysis investigates whether haemoglobin associates with investment in reproductive function in a rural natural fertility population living in the Bolivian .

Methodology: We conducted a cross-sectional secondary analysis of prospectively collected biomarker and sociodemographic data, comprising 152 menstrual cycles from 96 non-contracepting women living at 3800 m altitude.

Empowering rural communities for effective larval source management: A small-scale field evaluation of a community-led larviciding approach to control malaria in south-eastern Tanzania.

Introduction: Larval source management, particularly larviciding, is mainly implemented in urban settings to control malaria and other mosquito-borne diseases. In Tanzania, the government has recently expanded larviciding to rural settings across the country, but implementation faces multiple challenges, notably inadequate resources and limited know-how by technical staff. This study evaluated the potential of training community members to identify, characterize and target larval habitats of mosquitoes, the dominant vector of malaria transmission in south-eastern Tanzania.

'They will be like a person with a disease': a qualitative investigation of variation in contraceptive side-effect experiences in Central Oromia, Ethiopia.

Contraceptive side effects are consistently given as the main reason why women are dissatisfied with contraception or choose not to use it. However, why some women suffer more from side effects remains unknown. Through inductive analysis of in-depth interviews and focus group discussions with 40 contraceptive users and 3 key informants in Central Oromia, Ethiopia, we explored women's rationales for variation in side-effect experiences.

Cross-population variation in usage of a call combination: evidence of signal usage flexibility in wild bonobos.

The arbitrary relationship between signifier and signified is one of the features responsible for language's extreme lability, adaptability, and expressiveness. Understanding this arbitrariness and its emergence is essential in any account of the evolution of language. To shed light on the phylogeny of the phenomenon, comparative data examining the relationship between signal form and function in the communication systems of non-humans is central.

Modular morals: Mapping the organization of the moral brain.

Is morality the product of multiple domain-specific psychological mechanisms, or one domain-general mechanism? Previous research suggests that morality consists of a range of solutions to the problems of cooperation recurrent in human social life. This theory of 'morality as cooperation' suggests that there are (at least) seven specific moral domains: family values, group loyalty, reciprocity, heroism, deference, fairness and property rights. However, it is unclear how these types of morality are implemented at the neuroanatomical level.

The Intimate and Everyday Geopolitics of the Russian War Against Ukraine.

The contributions in this Forum analyse the Russian war against Ukraine from the micro perspective of everyday life, conveyed by scholars who have been impacted at a variety of personal levels. Framed within the existential threat that continues to endanger Ukrainians and Ukraine, the contributions collected here embrace the messiness of lived experience away from the grand narratives that circulate at global scales. Instead, the authors explore a variety of processes of situated bordering that fracture not just territory, but also families and individual lives.

The costs and benefits of kindness for kids.

What do children think makes an act kind? Which kind acts are children likely to perform? Previous research with adults suggests that the kindness of acts depends largely on the benefit provided and to a lesser extent on the cost incurred, and that adults are more likely to perform low-cost, high-benefit kind acts. In the current study, children (9-12 years, n = 945) and teens (13-17 years, n = 939) rated the benefit, cost, kindness, and likelihood of performing 173 acts of kindness, and adults (18+ years, n = 891) rated how beneficial, costly, kind, and likely the acts would be for young people to perform. Among children and teens, benefit but not cost predicted the kindness of acts, and benefit positively predicted, but cost negatively predicted, performance (for "kindness quotients" of 61% and 65%, respectively).

Biogeographical ‍distributions of trickster animals.

Human language encompasses almost endless potential for meaning, and folklore can theoretically incorporate themes beyond time and space. However, actual distributions of the themes are not always universal and their constraints remain unclear. Here, we specifically focused on zoological folklore and aimed to reveal what restricts the distribution of trickster animals in folklore.

Why care for humanity?

Some of the most pressing challenges facing our planet-such as climate change, biodiversity loss, warfare and extreme poverty-require social cohesion and prosocial action on a global scale. How can this be achieved? Previous research suggests that identity fusion-a strong form of group cohesion motivating prosocial action-results from perceptions of shared personally transformative experiences or of common biological essence. Here, we present results from two studies with United States samples exploring each pathway to identity fusion on a global scale.

Nutritional anthropology in the world.

Nutritional anthropology is the study of human subsistence, diet and nutrition in comparative social and evolutionary perspective. Many factors influence the nutritional health and well-being of populations, including evolutionary, ecological, social, cultural and historical ones. Most usually, biocultural approaches are used in nutritional anthropology, incorporating methods and theory from social science as well as nutritional and evolutionary science.

COVID-19 and abnormal uterine bleeding: potential associations and mechanisms.

The impact of COVID-19 on menstruation has received a high level of public and media interest. Despite this, uncertainty exists about the advice that women and people who menstruate should receive in relation to the expected impact of SARS-CoV-2 infection, long COVID or COVID-19 vaccination on menstruation. Furthermore, the mechanisms leading to these reported menstrual changes are poorly understood.

Translating models of obesity to tackle common obesity.

Tackling common obesity rests on having models of obesity that can be effectively translated into models for intervention; are we nearly there yet?

A broader theory of cooperation can better explain "purity".

Self-control provides one cooperative explanation for "purity." Other types of cooperation provide additional explanations. For example, individuals compete for status by displaying high-value social and sexual traits, which are moralised because they reduce the mutual costs of conflict.

Cross-national analyses require additional controls to account for the non-independence of nations.

Cross-national analyses test hypotheses about the drivers of variation in national outcomes. However, since nations are connected in various ways, such as via spatial proximity and shared cultural ancestry, cross-national analyses often violate assumptions of non-independence, inflating false positive rates. Here, we show that, despite being recognised as an important statistical pitfall for over 200 years, cross-national research in economics and psychology still does not sufficiently account for non-independence.