A valid evaluation of the theory of multiple intelligences is not yet possible: Problems of methodological quality for intervention studies

Since Gardner suggested that human beings hold multiple intelligences, numerous teachers have adapted and incorporated the multiple intelligence theory (MIT) into their daily routine in the classroom. However, to date, the efficacy of MIT–inspired methodologies remains unclear. The focus of the present study was to perform a systematic review and a meta–analysis to assess the impact of these interventions on academic achievement through reading, maths, or science tests. The inclusion criteria for the review required that studies should estimate quantitatively the impact of an MIT–based intervention on the academic performance and that they followed a pre–post design with a control group. The final sample included 39 articles comprising data from 3009 pre-school to high school students, with diverse levels of achievement, from 14 different countries. The results showed that the studies had important methodological flaws, like small sample sizes or lack of active control groups; they also reported insufficient information about key elements, such as the tools employed to measure the outcomes or the specific activities performed during training, and revealed signs of publication or reporting biases that impeded a valid evaluation of the efficacy of MIT applied in the classroom. The educational implications of these results are discussed.