In this randomized controlled trial, Baudouin et al. find that both pedagogical activities and a chatbot improve ninth graders’ attitudes and knowledge about vaccination, offering scalable ways to counter vaccine hesitancy in adolescents.

How do humans and large language models (LLMs) represent sentences? Liu et al. design a rule inference task revealing that both humans and LLMs implicitly decompose sentences into tree-structured constituents.

Herpell et al. use data from Germany to study the short- and medium-term effects of a programme to match Ukrainian refugees with private hosts on integration outcomes. Hosting led to improvements in social, psychological and navigational integration.

A network meta-analysis of 152 randomized controlled trials finds that personalized and group-customized digital interventions, especially SMS and app-based tools, improve smoking cessation versus standard care, with greater benefits among middle-aged adults in short- to medium-term programmes.

Yücel et al. examine how skin and hair characteristics impact functional near-infrared spectroscopy (fNIRS) signal quality and provide recommendations for inclusive use of fNIRS.

Boucherie et al. apply physics-based models to the arrangement of locations to study how geography shapes human movement. They find an underlying pattern in how people choose to move, independent of geographical layout.

Designing good research questions goes well beyond the standard definitions of clarity, focus and tractability, and even beyond ‘novelty’ in the strictest sense. This Comment describes the iterative creative process for designing good research questions, and includes practical suggestions and ways to avoid common traps.

Behaviour change interventions that are unsuccessful may often be limited by structural constraints. Accumulating evidence across contexts helps to diagnose these barriers. Policymakers should combine structural and behavioural insights to enact systemic reforms to better address environmental and societal challenges.

Despite its prominence in public discourse, economic growth does not translate into lasting improvements in well-being. To improve people’s lives, policymakers should shift their focus from economic growth to well-being. We provide example policies that could foster thriving, sustainable and inclusive societies.