Abstract Collective intelligence (CI) — the ability of groups to find solutions to problems and make decisions more effectively than their individual members — is a prominent feature of many group-living species, including our own. In this introductory article of the theme issue, we review and synthesize research concerning the evolution of CI from a range of disciplines, drawing in particular on the contributions made to the current issue. We describe mechanisms that generate CI and how they manifest across species, prompting insights into CI’s evolutionary history and phylogeny. We consider the functions and cognitive underpinnings of CI in the hominin lineage and in our own species, drawing on archaeological and ethnographic data. We summarize contemporary applied research and discuss the future of CI in human societies. Key questions raised in this introduction and tackled by the theme issue include: to what extent are different manifestations of CI across species phylogenetically related? How important are communication, deliberation or culture for leveraging the potential of groups? And how can scientific and technological advancements improve the human capacity for collective problem-solving and decision-making? This article is part of the theme issue ‘The evolution of collective intelligence’.
Seabright et al. (2026) studied this question.