Linguistic cleverness could have emerged with early grammar and verb-noun compounds creating expressive nouns. Skilled deployers of such compounds may have had higher reproductive fitness than less witty individuals.
A recent study published in PNAS Nexus found that large language models (LLMs) produce homogeneous creative outputs, regardless of the specific model used. This suggests that LLMs as a whole, rather than individual models, may be contributing to the lack of diversity in their responses.
The bow and arrow replaced the atlatl and dart as primary hunting technology in western North America, debuting around 1,400 years ago, with rapid adoption across the region
Research suggests that amyloid beta and tau proteins compete for microtubule binding sites, driving Alzheimer's disease pathology. The microtubule nexus hypothesis proposes a unifying theory for the underlying cause of Alzheimer's, with potential therapeutic strategies targeting tau displacement from microtubules.
Genetic analysis reveals the Tokara Leaf Warbler, a small insectivorous songbird, has been isolated from a similar species for 2.8-3.2 million years. The discovery suggests a need for reevaluation of conservation status due to threats from introduced weasels and environmental modification.
Researchers analyzed 2.2 million public statements from the 118th US Congress to understand the incentives behind divisive rhetoric. They found that a small minority of politicians, mostly Republicans, use personal insults to gain media attention, rather than policy gains.
Research suggests that modernization can increase cultural differences, rather than reducing them. Thomas Talhelm's study of China's rice- and wheat-growing regions found that families in rice-growing areas tend to be more collectivistic, living in large multigenerational households and less likely to live alone.
A study found that high heat stress does not reduce prosocial behavior, but cultural and gender differences significantly impact egalitarianism, resource maximization, and competitiveness. Women tend to exhibit more egalitarian behavior than men, while cultural differences affect specific elements of prosociality.
Research participants reading AI-generated summaries of historical events showed more liberal opinions than those reading Wikipedia summaries, indicating a subtle influence of AI biases on public understanding of the past. The study highlights the need for LLMs to be designed with bias-reducing features to provide unbiased information.
A microbe survived extreme pressures generated by a simulated Mars impact, suggesting it could withstand launch across space after major impacts. The hardy extremophile prioritized cellular repair and maintained structure in its cell envelope, enabling 60% survival of microbes.
Children exposed to opioids before birth face struggles in healthcare utilization and educational outcomes, with increased healthcare expenditures and special education services. Targeted interventions and integrated policymaking are needed to break the intergenerational cycle of opioid-related harm.
Researchers suggest ribosomes may have originated from a viral parasite, proposing a proto-ribosome that assembled small molecules into useful products. This theory implies that the evolution of the ribosome was influenced by its initial parasitic nature.
A study found that night lights affect two marine crustaceans differently, with Ligia laticarpa occurrence correlated to higher nighttime light intensity and Ligia furcata reduced activity under artificial lights. Night lights can structure ecosystems by acting as a barrier between lineages, potentially reducing gene flow.
A long-term survey analysis reveals stable individual measures of economic satisfaction, health, and happiness, but declining national confidence and institutional trust, with increased affective polarization and partisan divides.
A study using brain imaging identified the social and emotional features of wildlife photos that predict engagement on social media. The analysis found that animal faces and evolutionarily similar species in images boosted engagement and predicted actual likes on Instagram.
Researchers found Chinese chatbots more likely to refuse or provide inaccurate responses to sensitive questions about politics, while non-Chinese models offered longer, more accurate answers. The study suggests the source of this issue cannot be explained solely by training data or model development choices.
Researchers studied participants' ambulatory body image while learning to walk with a robotic leg. They found that participants initially underestimated and later overestimated their walking quality before incorporating the device into their body image.
A study found that AI-generated messages about public policies are highly persuasive, influencing policy views by an average of 9.74 percentage points. The study's results suggest that authorship labels have no significant impact on the persuasiveness of AI-generated content.
A resource redistribution experiment with Hadza adults suggests that egalitarianism is not primarily driven by a desire for equality, but rather by individual self-interest and norms of fairness. The results highlight the importance of extrinsic factors in shaping traditional sharing behaviors among hunter-gatherers.
Researchers propose an expansive mode of engineering practice that seeks to reduce conflict through the design of technologies like solar panels and water pipelines. The authors argue that procurement, education, and institutional support are necessary for peace engineering to become the norm.
Research finds that framing pro-environmental behavior as patriotic and highlighting successful examples of collective action significantly increase public awareness advocacy, financial advocacy, and political advocacy. This megastudy provides insights to guide those who wish to galvanize the public for collective climate action.
PhD students with high trust in their advisors report greater motivation, self-efficacy, and well-being, leading to more research submissions, fellowship awards, and a sense of accomplishment. Trust matters across demographic groups, suggesting its causal role in shaping a successful PhD journey.
A new computational framework detects repeated material across performances and maps its timing to visualize performance dynamics. The analysis reveals structural features, including consistently-placed new material and dense sections of tightly-timed content pillars.
A study analyzing 12 years of data found that artificial light at night was associated with earlier pollen season starts, longer seasons, and more severe allergen exposure. The effect on pollen season duration was larger than the effect on season start date.
Researchers incorporated factors like conflicts, natural hazards, and income inequality into human migration models, improving accuracy for South Sudan and US commuting patterns. The updated model outperforms a standard radiation model in predicting migrations.
A study found that women are more averse to risk in general and personally exposed to AI risks, but support AI use nearly as strongly as men when benefits are guaranteed. Women's skepticism towards AI is linked to higher risk orientation and exposure to AI-related jobs.
Researchers introduce a new citation index called 'nu' that balances productivity and citation quality, lying between the h-index and g-index. The authors propose a more balanced assessment of research impact by considering both productivity and citation quality.
A study in mice found that paternal immune activation affects small RNAs in sperm, leading to changes in offspring phenotypes such as increased body size and impaired insulin sensitivity. The findings suggest a potential mechanism for intergenerational transmission of health disorders.
Researchers developed an open-source robotic system to automate passaging of cells in 96-well microplates, reducing manual labor by 61% and improving consistency in cell density. The system also showed improved imaging site usability and increased experimental reproducibility.
The study simulates energy production and demand with hourly resolution and includes cross-border electricity transmission through a proposed ASEAN Power Grid. Technologies to create hydrogen gas would have to become much cheaper over time for this pathway to function.
Researchers found that pheomelanin helps maintain cysteine balance in cells by converting excess into inert pigment. This suggests why genetic variants promoting pheomelanin production persist despite increasing melanoma risk.
Researchers developed an AI model that detects unemployment-related social media posts with high precision, capturing nearly three times more disclosures than previous approaches. The method reduced forecasting errors by 54.3% compared to industry consensus forecasts and proved valuable during the COVID-19 pandemic.
Researchers found that diversifying crops and integrating livestock improves farm efficiencies and ecosystem services in the US Midwest. Increasing crop diversity results in up to 65% increase in productivity stability and 28% reduction in greenhouse gas emissions.
A study conducted during the 2024 French elections found that information about immigrants' deservingness traits, such as motivation to work and learn French, reduces negative beliefs about immigration. The intervention also produced modest reductions in opposition to immigration, with effects persisting one week after the intervention.
A study found that Japanese eels thrive in rivers with higher summer water temperatures, particularly those with farmland and urban land uses. Volcanic geology also plays a role, as younger formations result in cooler rivers and may limit the species' expansion.
A recent study found that Americans overestimate online toxicity, with participants believing 43% of Reddit users post toxic comments when only 3% actually do. Correcting this misperception improves social cohesion by reducing pessimism and increasing positivity.
Researchers developed a framework showing how cell membranes can produce transmembrane voltages through flexoelectricity, reaching up to 90 millivolts. Active biological processes create membrane fluctuations that drive ion transport against electrochemical gradients.
Researchers developed an algorithm to analyze publicly available radar imagery and identify destroyed buildings in conflict zones with precision up to 86%. The method enables democratized access to conflict monitoring tools and near real-time assessment of building destruction for humanitarian response and academic research.
A modeling study reveals that increasing numbers of households with rooftop solar panels can lead to higher rates for those without their own solar system. As the cost of solar systems falls, more customers defect from the grid, leading to increased rates and a 'utility death spiral' that disproportionately affects low-income households.
Researchers analyzed 12 years of hospital website data and found pixel tracking in 66% of observations, significantly increasing breach risk. Hospitals using third-party pixels saw a 1.4 percentage point increase in breach probability compared to baseline rates.
A recent study estimates that 22 million Americans exceed safe nitrogen dioxide exposure levels due to gas stove use. Gas stoves are found to be a significant source of indoor nitrogen dioxide emissions, particularly in households with multiple burners and oven usage.
Researchers found that people tend to find less energetic images more attractive, as they require fewer neurons and lower metabolic costs. This study suggests that our attraction to beauty may be an adaptive energy-conserving mechanism to optimize brain function.
Large language models (LLMs) exhibit network formation behaviors similar to humans, including preferential attachment, triadic closure, and homophily. In real-world simulations, LLMs prioritize homophily most strongly, followed by triadic closure and preferential attachment.
A cross-national study found that people tend to be more generous toward those from their own country or culturally similar nations. People from wealthy nations also shared more with less wealthy individuals, possibly to reduce global inequality.
Online experiments found that seeing only poor individuals reduces support for tax rates, while observing both rich and poor increases support for redistribution. However, this increased support can lead to higher polarization and conflict.
Seismic activity in Yellowstone's subsurface microbial communities led to changes in chemical energy and planktonic cell concentrations. The study found that kinetic energy from earthquakes can change the geochemical and microbial compositions of aquifer fluids.
The human costs of climate overshoot are a pressing concern, with policymakers needing to address humanitarian needs and disaster risk management. Assessing the potential impacts post-peak is necessary for identifying adaptation and risk reduction strategies.
A machine learning framework, LifeTracer, has been developed to analyze mass spectrometry data and identify patterns distinguishing abiotic from biotic origins. The framework achieved over 87% accuracy in classifying meteoritic and terrestrial samples, with key predictive features including polycyclic aromatic hydrocarbons.
Launched to promote scientific and technological ideas, PNAS Nexus has brought together experts from various fields. The journal's editorial board, comprising members of the National Academies, has fostered a multidisciplinary convergence in pursuit of useful purposes.
A new analysis of scientific documents found that 60-80% of citation paths led to sources without supporting data, revealing much wider uncertainty ranges for irrigation's impact on grain production and freshwater withdrawals. The study highlights the need to critically evaluate foundational claims in sustainability science.