Brookings Institution

The field of developmental science is increasingly interested in conducting research that is more representative, equitable, inclusive and generalizable. One way to achieve these aims is to conduct research that positions communities as key collaborators and central contributors to our scientific inquiries. These principles are evident in community science approaches like community-based participatory research (CBPR) and participatory action research (PAR). We argue that CBPR and PAR can be implemented by developmental scientists. Here, we describe two initiatives that utilized CBPR and PAR. The first initiative is Playful Learning Landscapes (PLL). PLL embeds research from the learning sciences into public spaces to offer playful learning opportunities for children and families, and community science practices are leveraged throughout the process. The second initiative is the Galápagos Education and Research Alliance (GERA). GERA harnesses the tools of community science by working directly with communities in the fragile environment of Galápagos to gather data about ecosystem health and build community-based plans for climate change adaptation. Together, these two initiatives offer rich examples of how CBPR and PAR principles engender active participation from the community throughout the design and evaluation of a research project. We discuss the opportunities and challenges of using community-centred approaches.

The financing of long-term care services and supports (LTSS) relies heavily on self-insurance in the form of housing or financial wealth. Exploiting both local market variation in housing prices and individual-level variation in stock market wealth from 1996 to 2016, we show that exogenous wealth shocks significantly reduce the probability of LTCI coverage, without altering Medicaid eligibility among people with housing and financial assets. The effect of shocks to liquid wealth strongly dominates the effect of housing wealth changes. A $100 K increase in housing (financial) wealth reduces the likelihood of LTCI coverage by 1.24 (3.22) percentage points.

Large language models (LLMs) are increasingly used for mental health, yet safety evaluations rely primarily on small, simulation-based benchmarks removed from real-world language. We replicate four published safety evaluations assessing suicide risk handling, harmful content generation, and jailbreak resistance for general-purpose frontier models and a purpose-built mental health AI. We then conduct an ecological audit of 20,000 real user conversations with the purpose-built system, which includes layered safeguards for suicide and non-suicidal self-injury (NSSI). The purpose-built AI was significantly less likely than general-purpose LLMs to produce harmful content across suicide/NSSI (.4-11.27% vs 29.0-54.4%), eating disorder (8.4% vs 54.0%), and substance use (9.9% vs 45.0%) benchmarks. In real user data, clinician review found zero suicide-risk cases without crisis resources. Three NSSI mentions (.015%) lacked intervention, implying a .38% lower-bound false negative rate. Findings support the utility of ecological audits for safety estimation.

Abstract Humans are not omniscient. For individuals, appropriately reckoning with intellectual limitations requires intellectual humility or acknowledging the boundaries of their knowledge. Adolescence is a time of immense developmental potential, but is intellectual humility valuable for adolescents to develop, can they develop it, and how might it be developed? Rooted in recent research, in this article, we describe why intellectual humility benefits adolescents in intellectual, social, and civic domains. We also explain why adolescents have the capacity to develop intellectual humility due to developmental changes in both cognitive sophistication and self-understanding. Finally, drawing on an emerging evidence base, we describe how experiences in school shape the development of intellectual humility and we identify priorities for future work in this area.

Research managers and investors need better approaches to weigh risks and potential benefits of scalable, transformational technologies.

Asymptotic giant branch (AGB) stars, which are evolved low- to intermediate-mass stars, rank among the most prolific producers of interstellar dust in the Galaxy. Presolar silicon carbide (SiC) grains in meteorites are mainly produced by AGB stars. These presolar grains contain abundant noble gases, believed to have been implanted by stellar winds from the central stars of planetary nebulae (CSPNe). Here we report 3-D maps of the helium distribution in individual presolar SiC grains. The maps reveal that the implantation energy of 4He for individual grains varies from about 2 to about 4 keV/nucleon, which falls within the range of the CSPN winds. The variation of 4He fluence (1×1012–2×1015 atom cm–2) shows that the SiC grains form during the last about 1 My period of the AGB star phase. Then, they migrate outwards and become exposed to CSPN winds at distances of 0.3–32 light-years from the CSPNe.

Abstract Polyploidization played a crucial role in crop domestication and modern agriculture. While increased cell size in polyploids is known to enhance plant biomass and vigor, its impact on soil exploration remains poorly understood. Using wheat as a model, we identify a ploidy-induced belowground domestication syndrome, characterized by (a) increased root cortical cell size reducing root respiration, nitrogen content, and phosphorus content; (b) enlarged metaxylem vessels, increasing axial hydraulic conductance; and (c) blunter root tips, limiting penetration ability in compacted soils. Our empirical and in silico experiments show that reduced root respiration and reduced cellular nutrient content in wheat polyploids improved nutrient use and acquisition efficiency under suboptimal nitrogen and phosphorus availability. These adaptations would have been advantageous in nutrient-depleted agroecosystems of the Pre-Pottery Neolithic B (PPNB) Fertile Crescent, where continuous cultivation depleted soil fertility over time. Functional-structural modeling indicates that larger cortical cells in wheat polyploids increase vacuolar occupancy, reducing root metabolic costs. Enhanced axial hydraulic conducta nce may have improved water transport, an advantage in irrigated PPNB agroecosystems. However, polyploids have blunter root tips, which reduces their penetration ability in compacted soils, making them less suited for native soils with greater mechanical impedance. We propose that root anatomical changes driven by ploidy played an important role in adaptations of wheat domesticates to PPNB agriculture. One-Sentence Summary Polyploidy induced changes in root anatomy may have improved adaptation of wheat to Neolithic agroecosystems.