“…On the other hand, if we analyse the relationship between the main characteristics of the SEL programmes included in this systematic review and their effectiveness, we can see that the interventions that have been developed in out-of-school time (e.g., Santos et al, 2013;Salgado and Marques-Pinto, 2017), that employ video games (e.g., Cejudo et al, 2020) or alternative sports (e.g., Luna et al, 2019) among their procedures, practices, strategies, techniques and/or resources, with exclusively compulsory secondary education population (e.g., Castillo et al, 2013;Rodríguez-Ledo et al, 2018;Luna et al, 2019;Cejudo et al, 2020), are associated to a greater extent with a lower impact on the dependent variables considered, yielding results that are not statistically significant. Quite the opposite happens with those SEL programmes implemented in school time, as part of the curriculum, in which teachers and/or responsible external staff are trained to carry out a sequenced, active, focused, and explicit SEL training with the participating students (e.g., Milicic et al, 2013;Coelho et al, 2014Coelho et al, , 2015Coelho et al, , 2016aBerger et al, 2014;Waldemar et al, 2016;Coelho and Sousa, 2017a,b;Coelho and Sousa, 2018;Mira-Galvañ and Gilar-Corbi, 2020), as they reveal a greater impact on socioemotional competencies, well-being, and school achievement.…”