Challenging the illusion: Evaluating the effectiveness of an ultra-brief emotional intelligence intervention on Spanish children's psychosocial adjustment.

The development of Social and Emotional Learning (SEL) is of increasing interest in schools worldwide. Consequently, the evaluation of SEL programs such as emotional intelligence (EI) interventions, to ensure the establishment of evidence-based emotional education is relevant. The main purpose of this study was to evaluate the effects of an ultra-short (6 h) EI intervention on child psychosocial adjustment. The sample consisted of 268 children (8-12 years old). Results from ANCOVA analyses showed no statistically significant differences between the intervention and control groups at post-test across the main outcome variables (e.g., F values .12), though within-group Student's t-tests revealed small but significant improvements in quality of life at post-test (d = 0.18) and in quality of life, mental health (d = 0.48), and anxiety/depression symptoms (d = 0.11) at one-year follow-up in the intervention group. These findings revealed the absence of differences between experimental and control groups at post-test, although the intervention group significantly increased health-related quality of life at post-test and follow-up, as well as mental health at follow-up assessment. This paper highlights the great importance of the way elected to evaluate the overall effectiveness of an EI intervention based on using hard techniques (i.e., ANCOVA), showing actual effectiveness, versus soft contrast techniques (e.g., Student's t-test, Repeated-Measures ANOVA), which simply show gains (fake effects). The importance of ensuring hard evidence-based emotional education is highlighted. These findings underscore the relevance of using rigorous statistical techniques-so-called hard methods like ANCOVA-to avoid inflated or false-positive interpretations often derived from gain-score analyses (fake effects) in the evaluation of overall effectiveness of an EI intervention. Overall, the intervention showed limited but promising effects, particularly in long-term mental health, suggesting potential for brief SEL programs if implemented and assessed with methodological rigor.