How much good would teaching mindfulness to children do? Research built up over the past two decades has not been scant, but concerns about wide variation in the results have also been persistent. A US research team has pointed to the meditation habits of the people carrying out the studies as one of the factors behind that variation. The finding comes from a re-calculation after collecting 107 studies of mindfulness-based interventions targeting children and adolescents. The paper was published in volume 95, issue 4 of the journal Psychotherapy and Psychosomatics.
They brought together data from 8,510 people
The analysis included 107 mindfulness-based intervention studies involving children and adolescents, 1,393 statistical measures and data from 8,510 participants. With an average age of around 12 (a range of roughly 4 to 19), the study is the largest among mindfulness meta-analyses for children and adolescents conducted to date. The research team calculated the effect sizes for each study and, at the same time, coded the meditation experience that the paper’s authors themselves reported. The three measures were the time spent meditating in the past 24 hours, the number of meditation sessions in the past seven days, and the number of years they had sustained the practice.
The overall effect size was Hedge’s g 0.33 (95% confidence interval 0.27 to 0.39, p〈0.001). It falls between small and moderate. The result does not differ greatly from the conclusion that mindfulness programmes do help children, but the impact is not dramatic. Earlier meta-analyses have reported similar ranges too (Hedge’s g 0.31 to 0.32, Cohen’s d 0.16 to 0.30).
The split came down to researchers’ recent practice
The differences showed up elsewhere. In studies conducted by people who had meditated for at least 30 minutes within the previous 24 hours, the effect size rose to g 0.51 (95% CI 0.35 to 0.66, p=0.05). In studies led by people who had sat at least seven times within the previous seven days, it was g 0.52 (95% CI 0.39 to 0.65, p〈0.01). That is more than 1.5 times the overall average.
By contrast, meditation experience, which refers to how many years the practice had been sustained, was not linked to effect size (p=0.17). It was not a question of whether someone had been doing it for a long time; rather, whether they were actually sitting in this period was the dividing line. Of 97 researchers who responded to the survey, 95% said they had tried meditation at least once in their lifetime, but only 57% reported meditating within the past 24 hours. In other words, most researchers had meditation experience, yet the length of that experience was unrelated to outcomes, while only their recent actual practice predicted the results.
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Why did this difference arise?
The paper does not make a firm claim about causation. Instead, it offers three possible interpretations. First, a competence effect: researchers who directly practise meditation may understand subtle aspects of mindfulness literature and the intervention design and teaching methods better, producing better outcomes. Second, an environment effect: research groups led by practitioners with deeper experience may operate in a warm, attentive atmosphere, improving the quality of programme delivery. Third, a passion effect: researchers who believe in the efficacy of mindfulness and practise it themselves may, without realising, have skewed how they designed, collected and interpreted the data in their favour. There is also room for the possibility that other differences lie hidden between studies that provide detailed accounts of practice history and those that do not.
What is interesting is that the analysis found no evidence of publication bias. To overturn the result, an additional 185 meaningless studies would have to be published, and even after adjustment the effect size remained significant at g 0.22. It also varied by region: the studies carried out in Asia had an effect size of g 0.54, notably larger than those from other continents (North America 0.35, Europe 0.28, Australia 0.12). The paper noted that because mindfulness originated in Buddhist practice, programmes may have been received more naturally in Buddhist culture in terms of language, metaphors and the teacher–student relationship.
The corresponding authors are David C. Saunders in the Department of Psychiatry at Columbia University and Hedy Kober in the Department of Psychology at the University of California, Berkeley. The co-authors are based at the Department of Psychiatry and the Yale Child Study Center at Yale University. The researchers’ meditation practice histories were collected via an online survey under approval from Yale’s institutional review board.
Questions that remain for mindfulness in schools at home
In South Korea too, mindfulness programmes for children and adolescents are increasingly being rolled out, focused on schools and local governments. From 2004 to 2024, there are already 67 mindfulness studies for children and adolescents published in domestic journals, and effect sizes for mindfulness-based interventions targeting teenagers have been reported at between 0.85 and 1.02, with positive results steadily accumulating.
The question this study raises sits before the content of programmes or the number of sessions. It is whether the person teaching is continuing their own practice, and whether a supporting structure has been built into the programme. In training courses for leaders, the required hours and qualifications are covered relatively thoroughly, but how to support a leader’s continuing personal practice has been discussed far less. The paper’s authors said they hope the findings will prompt a re-examination in mindfulness research of the influence that an individual researcher’s own experience can have. Guaranteeing the leader’s time for practice and designing regular personal practice as part of the programme could be one pillar of the answer.
