Philosophy For & With Children: A Meta-Analysis of Evidence

There has been a growing interest among educators and policymakers in approaches that go beyond traditional subject-based teaching to foster deeper cognitive and social skills in students. One such approach, Philosophy for/with Children (P4wC), has attracted widespread attention for its potential to nurture critical, creative, and collaborative thinking from an early age. As schools around the world increasingly seek evidence-based methods to cultivate these capacities, robust empirical research is needed to clarify exactly what benefits P4wC can deliver and for whom. Ben Kilby’s 2025 meta-analysis, published in the International Journal of Contemporary Educational Research, directly addresses this need by systematically reviewing and synthesising decades of quantitative research on the impact of P4wC. By drawing on 62 datasets from 30 controlled studies across diverse educational contexts, Kilby’s work not only updates the field with the most current evidence but also provides nuanced insights into where and how P4wC is most effective. This article is particularly important because it moves the discussion of philosophy in schools beyond anecdote and advocacy, offering clear, data-driven conclusions about its educational value, especially in the development of critical thinking. For educators, school leaders, and all those interested in the future of education, Kilby’s findings offer both a rationale and a roadmap for integrating philosophical inquiry into curricula with the aim of preparing students for thoughtful, reflective, and engaged participation in society.

Summary and Key Findings of "Philosophy for/with Children: A Meta-Analysis" by Ben Kilby
(For Educators – Long Essay)

Ben Kilby’s 2025 meta-analysis represents one of the most comprehensive and up-to-date examinations of the empirical evidence for the educational benefits of Philosophy for/with Children (P4wC). For educators, this study is highly significant, not only in confirming the substantial impact of P4wC on students’ critical thinking, but also in clarifying the boundaries of what can and cannot be claimed for this educational approach.

Understanding P4wC: Origins and Evolution

P4wC originated in the 1970s with American philosopher Matthew Lipman, who, inspired by pragmatism and dismayed by the lack of creative and critical thinking in mainstream education, developed curricula centred around philosophical dialogue for young people. The key principle was not to transmit knowledge of philosophers or philosophical theories, but to foster children’s own capacities for inquiry, reasonableness, and collaborative discussion—qualities deemed essential for participation in society and lifelong learning. Over the decades, the P4wC movement has broadened and diversified, now present at all levels of education, and encompassing both analytical thinking and more affective, creative, and caring dimensions.

Kilby’s analysis takes a deliberately inclusive stance, recognising that terminology and practice vary (with “Philosophy for Children,” “Philosophy with Children,” “philosophy in schools,” and similar all referring to a shared family of approaches). Importantly, the pedagogical heart of P4wC is dialogic: children and teachers together explore philosophically challenging concepts, such as justice, truth, beauty, and freedom, not to memorise answers, but to become better thinkers, questioners, and collaborators. The goal is a "philosophiser" rather than a historian of philosophy.

Scope and Methodology of the Meta-Analysis

To provide an updated assessment of P4wC, Kilby systematically identified 30 studies (yielding 62 datasets) that met rigorous inclusion criteria: each had to feature a quantitative, controlled design, allowing calculation of effect sizes using the Hedges G method. The outcomes measured included not just critical thinking, but also reading, general academic achievement, and socio-emotional learning, giving a broad view of P4wC’s impact.

This new analysis builds upon earlier meta-analyses (notably Trickey & Topping, 2004, and Moriyón et al., 2005) but is distinguished by its inclusion of more recent studies and its careful statistical recalibration, ensuring all effect sizes are directly comparable.

Key Findings: Significant Educational Impact

The headline result is striking: P4wC interventions produce a statistically significant, moderate-to-large overall effect size of 0.65. This places P4wC among the most effective educational strategies, as benchmarks from Hattie (2020) and others suggest an effect size of 0.40 is typical for educational interventions. Notably, this figure is higher than that reported in most previous meta-analyses, likely reflecting methodological improvements and the inclusion of newer studies.

More detailed analysis reveals that this impact is not restricted to a particular age group. Children in early childhood (>8 years) and those in middle years (8–14 years) benefit equally, with effect sizes of 0.73 and 0.75 respectively. This finding counters any lingering assumptions that philosophy is only suitable for older or especially able students. It is clear from the data that the foundations of critical thinking can be successfully laid in primary and even early childhood education.

Geographical differences are also revealing. Studies conducted in “Eastern” contexts (broadly, educational systems with more traditional, teacher-led pedagogies) reported higher effect sizes (0.89) than those in “Western” contexts (0.56). One plausible explanation is that the dialogic and open-ended inquiry promoted by P4wC is particularly transformative in settings where it is a marked contrast to prevailing methods.

However, the most pronounced effect is found in the domain of critical thinking. When studies focused specifically on this outcome, the effect size rose to 0.89—by any standard, a very strong result. By contrast, effect sizes for general academic achievement and reading were smaller (about 0.36), and only marginally or not statistically significant. Measures of socio-emotional learning appeared promising but were based on a small number of datasets and were thus too variable for firm conclusions.

Implications and Recommendations for Educators

For teachers and school leaders, several clear messages emerge from Kilby’s analysis.

First, P4wC is a robust and well-evidenced way to enhance students’ critical thinking. This is its primary and most reliable benefit, as shown consistently across contexts and age groups. If schools are seeking to develop their students’ capacities for reasoning, dialogue, and reflective judgement, P4wC offers a proven methodology.

Second, P4wC’s benefits are not confined to high-ability or older students. The evidence supports the introduction of philosophical inquiry in early and primary education, allowing the cultivation of thinking skills from the earliest years of schooling.

Third, while there are some gains in reading and general academic achievement, these are modest and not the main reason to adopt P4wC. Efforts to justify philosophy in schools on the grounds of improving standardised test scores in literacy or numeracy are not well supported by the quantitative evidence. Rather, P4wC should be understood and promoted as a distinctive contribution to education, fostering capacities that may not be directly captured in conventional assessments.

Fourth, context matters. Schools in educational systems that are less accustomed to open dialogue and inquiry may find that the impact of P4wC is even greater. Nevertheless, even in Western contexts, the effect is strong enough to justify its inclusion as part of a broad, modern education.

Finally, Kilby is careful to point out that many of the most valued outcomes of P4wC—such as intellectual humility, the ability to listen and care for others’ viewpoints, and the growth of ethical or creative dispositions—are not easily measured by quantitative means. Future research and educational practice should give greater attention to these aspects, even as the quantitative evidence for critical thinking is now clear.

Conclusion

Ben Kilby’s meta-analysis reaffirms P4wC as a highly effective educational intervention, especially for developing critical thinking in children and young people. Its efficacy is robust across ages and especially powerful in educational settings where open inquiry is less common. For educators, the message is straightforward: philosophy is not a luxury or an esoteric pursuit, but a practical, evidence-based approach to nurturing the kind of thinking needed in modern societies. Schools should consider adopting or expanding P4wC, not primarily to boost reading or general academic scores, but to create communities of inquiry in which children learn to think with clarity, creativity, care, and courage—skills that serve them for a lifetime.