More than 1.3 million people die each year as a result of violence (World Health Organization [WHO], 2014).

In the Basque country, in the past year, 83.7% of adolescents have been involved in situations of bullying, and 69.8% in cyberbullying (Garaigordobil, 2013). A possible response is to develop emotional intelligence (EI).

Thus, adolescents with more emotional skills present fewer negative emotions related to the expression of aggressive behavior, such as anger and hostility (Extremera and Fernández-Berrocal, 2013).

assessing the effects of the dating violence prevention-3

Regarding the effect of the program on both genders, the change was very similar, but the boys increased assertive social interaction strategies, attention, and emotional clarity significantly more than the girls.

The importance of implementing programs to promote socio-emotional development and prevent violence is discussed.

Currently, problems like bullying, racism, sexism, loneliness, depression, etc., are common and all of them are related to social and emotional skills. Studies examining the relationship between aggressive behavior and EI are scarce (Inglés et al., 2014).

Still, these studies show that emotional attention is positively related to anger, and that greater clarity and emotion repair are related to lower trait/state anger, lower internal expression of anger, and higher anger control (Salguero and Iruarrizaga, 2006).

The study aimed to design a program of EI for adolescents and to assess its effects on variables related to violence prevention.

If the program teaches adolescents to moderate their negative emotions, intensifying the positive ones, internally control their feelings of anger, increase their knowledge of assertive strategies for coping with problematic social situations, or become more aware of the harmful consequences of negative emotions for themselves and for others, then their violent behavior is expected to decrease.

To measure the variables, four assessment instruments were administered before and after the program, as well as in the follow-up phase (1 year after the conclusion of the intervention). The pretest–posttest ANCOVAs showed that the program significantly increased: (1) EI (attention, clarity, emotional repair); (2) assertive cognitive social interaction strategies; (3) internal control of anger; and (4) the cognitive ability to analyze negative feelings.

In the follow-up phase, the positive effects of the intervention were generally maintained and, moreover, the use of aggressive strategies as an interpersonal conflict-resolution technique was significantly reduced.

The theoretical framework of this study is based on the model of Mayer and Salovey (1997), in which EI is made up of four dimensions: perception, facilitation, comprehension, and emotion regulation.