Uncovering individualised treatment effects for educational trials.

Large-scale Randomised Controlled Trials (RCTs) are widely regarded as "the gold standard" for testing the causal effects of school-based interventions. RCTs typically present the statistical significance of the average treatment effect (ATE), which captures the effect an intervention has had on average for a given population. However, key decisions in child health and education are often about individuals who may be very different from those averages.

Selective insensitivity to income held by the richest.

The misperception of income inequality is often touted as a critical barrier to more widespread support of redistributive policies. Here, we examine to what extent and why (mis)perceptions vary systematically across the income distribution. Drawing on data from four studies ( = 2,744)-including a representative sample and preregistered incentive-compatible experiments-we offer converging evidence that people specifically underestimate the amount of income held by the top of the income distribution.

Generative AI enhances individual creativity but reduces the collective diversity of novel content.

Creativity is core to being human. Generative artificial intelligence (AI)-including powerful large language models (LLMs)-holds promise for humans to be more creative by offering new ideas, or less creative by anchoring on generative AI ideas. We study the causal impact of generative AI ideas on the production of short stories in an online experiment where some writers obtained story ideas from an LLM.

Reducing discrimination against job seekers with and without employment gaps.

Past research shows that decision-makers discriminate against applicants with career breaks. Career breaks are common due to caring responsibilities, especially for working mothers, thereby leaving job seekers with employment gaps on their résumés. In a preregistered audit field experiment in the United Kingdom (n = 9,022), we show that rewriting a résumé so that previously held jobs are listed with the number of years worked (instead of employment dates) increases callbacks from real employers compared to résumés without employment gaps by approximately 8%, and with employment gaps by 15%.

Deception about study purpose does not affect participant behavior.

The use of deception in research is divisive along disciplinary lines. Whereas psychologists argue that deception may be necessary to obtain unbiased measures, economists hold that deception can generate suspicion of researchers, invalidating measures and 'poisoning' the participant pool for others. However, experimental studies on the effects of deception, notably false-purpose deception-the most common form of experimental deception-are scarce.

Measuring inequality beyond the Gini coefficient may clarify conflicting findings.

Prior research has found mixed results on how economic inequality is related to various outcomes. These contradicting findings may in part stem from a predominant focus on the Gini coefficient, which only narrowly captures inequality. Here, we conceptualize the measurement of inequality as a data reduction task of income distributions.

Human-centred mechanism design with Democratic AI.

Building artificial intelligence (AI) that aligns with human values is an unsolved problem. Here we developed a human-in-the-loop research pipeline called Democratic AI, in which reinforcement learning is used to design a social mechanism that humans prefer by majority. A large group of humans played an online investment game that involved deciding whether to keep a monetary endowment or to share it with others for collective benefit.

Climate Action for (My) Children.

How do we motivate cooperation across the generations-between parents and children? Here we study voluntary climate action (VCA), which is costly to today's decision-makers but essential to enable sustainable living for future generations. We predict that "offspring observability" is critical: parents will be more likely to invest in VCA when their own offspring observes their action, whereas when adults or genetically unrelated children observe them, the effect will be smaller. In a large-scale lab-in-the-field experiment, we observe a remarkable magnitude of VCA: parents invest 82% of their 69€ endowment into VCA, resulting in almost 14,000 real trees being planted.

(Mis)perceiving cooperativeness.

Cooperation is crucial for the success of social interactions. Given its importance, humans should readily be able to use available cues to predict how likely others are to cooperate. Here, we review the empirical literature on how accurate such predictions are.

Ideology selectively shapes attention to inequality.

Contemporary debates about addressing inequality require a common, accurate understanding of the scope of the issue at hand. Yet little is known about who notices inequality in the world around them and when. Across five studies ( = 8,779) employing various paradigms, we consider the role of ideological beliefs about the desirability of social equality in shaping individuals' attention to-and accuracy in detecting-inequality across the class, gender, and racial domains.

Abrupt decline in tropospheric nitrogen dioxide over China after the outbreak of COVID-19.

China's policy interventions to reduce the spread of the coronavirus disease 2019 have environmental and economic impacts. Tropospheric nitrogen dioxide indicates economic activities, as nitrogen dioxide is primarily emitted from fossil fuel consumption. Satellite measurements show a 48% drop in tropospheric nitrogen dioxide vertical column densities from the 20 days averaged before the 2020 Lunar New Year to the 20 days averaged after.

Evolving cooperation in multichannel games.

Humans routinely engage in many distinct interactions in parallel. Team members collaborate on several concurrent projects, and even whole nations interact with each other across a variety of issues, including trade, climate change and security. Yet the existing theory of direct reciprocity studies isolated repeated games.

Social dilemmas among unequals.

Direct reciprocity is a powerful mechanism for the evolution of cooperation on the basis of repeated interactions. It requires that interacting individuals are sufficiently equal, such that everyone faces similar consequences when they cooperate or defect. Yet inequality is ubiquitous among humans and is generally considered to undermine cooperation and welfare.

The critical role of second-order normative beliefs in predicting energy conservation.

Sustaining large-scale public goods requires individuals to make environmentally friendly decisions today to benefit future generations. Recent research suggests that second-order normative beliefs are more powerful predictors of behaviour than first-order personal beliefs. We explored the role that second-order normative beliefs-the belief that community members think that saving energy helps the environment-play in curbing energy use.

(Mis)perceptions of inequality.

Laypeople's beliefs about the current distribution of outcomes such as income and wealth in their country influence their attitudes toward issues ranging from taxation to healthcare - but how accurate are these beliefs? We review the burgeoning literature on (mis)perceptions of inequality. First, we show that people on average misperceive current levels of inequality, typically underestimating the extent of inequality in their country. Second, we delineate potential causes of these misperceptions, including people's overreliance on cues from their local environment, leading to their erroneous beliefs about both the overall distributions of wealth and income and their place in those distributions.

Failure to CAPTCHA Attention: Null Results from an Honesty Priming Experiment in Guatemala.

We report results from a large online randomised tax experiment in Guatemala. The trial involves short messages and choices presented to taxpayers as part of a CAPTCHA pop-up window immediately before they file a tax return, with the aim of priming honest declarations. In total our sample includes 627,242 taxpayers and 3,232,430 tax declarations made over four months.

Think global, act local: Preserving the global commons.

Preserving global public goods, such as the planet's ecosystem, depends on large-scale cooperation, which is difficult to achieve because the standard reciprocity mechanisms weaken in large groups. Here we demonstrate a method by which reciprocity can maintain cooperation in a large-scale public goods game (PGG). In a first experiment, participants in groups of on average 39 people play one round of a Prisoner's Dilemma (PD) with their two nearest neighbours on a cyclic network after each PGG round.

Cooperating with the future.

Overexploitation of renewable resources today has a high cost on the welfare of future generations. Unlike in other public goods games, however, future generations cannot reciprocate actions made today. What mechanisms can maintain cooperation with the future? To answer this question, we devise a new experimental paradigm, the 'Intergenerational Goods Game'.

Heterogeneity in background fitness acts as a suppressor of selection.

We introduce the concept of heterogeneity in background fitness to evolutionary dynamics in finite populations. Background fitness is specific to an individual but not linked to its strategy. It can be thought of as a property that is related to the physical or societal position of an individual, but is not dependent on the strategy that is adopted in the evolutionary process under consideration.

Simple and effective ultrasound needle guidance system.

In this paper, we describe our prototype of an ultrasound guidance system to address the need for an easy-to-use, cost-effective, and portable technology to improve ultrasound-guided procedures. The system consists of a lockable, articulating needle guide that attaches to an ultrasound probe and a user-interface that provides real-time visualization of the predicted needle trajectory overlaid on the ultrasound image. Our needle guide ensures proper needle alignment with the ultrasound imaging plane.

Creation of a prevascularized site for cell transplantation in rats.

Introduction: Transplanted cells, especially islet cells, are likely to become apoptotic due to local hypoxia leading to graft dysfunction. Isolated pancreatic islet cells depend on the diffusion of oxygen from the surrounding tissue; therefore, access to sufficient oxygen supply is beneficial, particularly when microcapsules are used for immunoisolation in xenotransplantation. The aim of this study was to create a prevascularized site for cell transplantation in rats and test its effectiveness with microencapsulated HEK293 cells.

Encapsulated, genetically modified cells producing in vivo therapeutics.

The ability to implant genetically modified cells in immuno-isolating materials has much potential for therapeutic use. This review presents the different types of polymer that can be used for encapsulation of cells and the recent use of genetically modified, encapsulated and thus immunoprotected cells for the treatment of diseases in animal models and clinical trials. Some of the challenges faced by these technologies and potential solutions are also discussed.

Identification of 1088 new transposon insertions of Caenorhabditis elegans: a pilot study toward large-scale screens.

We explored the feasibility of a strategy based on transposons to generate identified mutants of most Caenorhabditis elegans genes. A total of 1088 random new insertions of C. elegans transposons Tc1, Tc3, and Tc5 were identified by anchored PCR, some of which result in a mutant phenotype.