I’ve not seen this previously, but here is a link to a 2009 study on “Martial arts as a mental health intervention for children.”
I’ve copied the summary below and drew out some parts I found important.
The conclusion is that, on average, there is no evidence to support the idea that martial arts practise will promote mental health outcomes such as self-esteem, self-confidence, concentration, and self-discipline in children.
However, they do note that the “average” may be a result of the good and bad schools effectively cancelling each other out i.e. one school does help develop self-control, another fosters aggression.
I’m sure all here can recount the tales where martial arts have done wonders for children. I’ve certainly seen that many times. And as someone who started practising as a children I know that it has had a hugely positive effect on me.
The bottom line, it seems to me, is that this underlines the need to avoid “average schools” and go to ones that get demonstrable results.
It’s an interesting one for discussion and thanks to @LJAthletics on Twitter for making me aware of it.
All the best,
Martial arts studios for children market their services as providing mental health outcomes such as self-esteem, self-confidence, concentration, and self-discipline. It appears that many parents enroll their children in martial arts in hopes of obtaining such outcomes. The current study used the data from the Early Childhood Longitudinal Study, Kindergarten class of 1998-1999, to assess the effects of martial arts upon such outcomes as rated by classroom teachers.
The Early Childhood Longitudinal Study used a multistage probability sampling design togather a sample representative of U.S. children attending kindergarten beginning 1998. We made use of data collected in the kindergarten, 3rd grade, and 5th grade years. Classroom behaviour was measured by a rating scale completed by teachers; participation in martial arts was assessed as part of a parent interview. The four possible combinations of participation and nonparticipation in martial arts at time 1 and time 2 for each analysis were coded into three dichotomous variables; the set of three variables constituted the measure of participation studied through regression.
Multiple regression was used to estimate the association between martial arts participation and change in classroom behavior from one measurement occasion to the next. The change from kindergarten to third grade was studied as a function of martial arts participation, and the analysis was replicated studying behavior change from third grade to fifth grade. Cohen's f2 effect sizes were derived from these regressions.
The martial arts variable failed to show a statistically significant effect on behavior, in either of the regression analyses; in fact, the f2 effect size for martial arts was 0.000 for both analyses. The 95% confidence intervals for regression coefficients for martial arts variables have upper and lower bounds that are all close to zero. The analyses not only fail to reject the null hypothesis, but also render unlikely a population effect size that differs greatly from zero.
The data from the ECLS-K fail to support enrolling children in martial arts to improve mental health outcomes as measured by classroom teachers.
An important limitation of this study is that the ECLS-K gathered only one bit of information on the child's martial arts participation at any given measurement occasion. A study designed specifically to assess the effect of martial arts would have gathered data on the start and end dates and frequency of training, and the specific curricula of the various studios. It is conceivable that we failed to find effects because too few students persisted at the study of martial arts long enough. We would be very curious to know the average length of training.
… It does seem to us that if martial arts were, on the average, as effective an intervention as its proponents believe, participation as measured by the simple answer to whether the child is participating in martial arts would have revealed at least a tiny visible effect, given the more than adequate sample size and given the reliability of the behavior rating variable.
The claims of martial arts studios and the expectations of many parents that martial arts will improve self-control and self-confidence contrast with the near-zero effect sizes found in these analyses. Changing students' behavior outside the classroom in a way that generalizes to the classroom is, we suspect, in general not an easy task. This study fails to find evidence that martial arts training achieves this goal.
It's important to remind ourselves that educational interventions such as martial arts are not homogeneous. Martial arts as taught by one practitioner may be totally different from that taught by another. One practitioner may emphasize self-control and emotional regulation, whereas another might emphasize self-defense or preparation for competition, and a third might actually promote aggression; the intervention can be very different depending on who is teaching it. Thus it is possible that the close-to-zero effects that we report here are an average of positive and negative effects. Thus our results do not rule out the possibility that some studios regularly achieve positive effects, and others achieve negative ones. It could also be that even within individual studios, there are net positive effects on some children from encouraging self-discipline and respect, which are cancelled by net negative effects on others from practice of physical aggression. The current study probably offers a reasonable estimate of the effect on classroom behavior of enrolling an elementary school child in "the average" U.S. martial arts studio; and continuing training an "average" length of time. The estimate for such training is a zero effect.