INMA:”Bullying from a biopsychosocial perspective: A study of the INMA project integrates hormonal markers to the study of bullying”


A study conducted as part of the INMA cohort studied bullying from a biopsychosocial perspective, integrating biological variables such as hormone levels into bullying behavior.

Bullying is defined as a type of aggressive behavior that occurs in the school context and typically occurs during childhood and adolescence. Despite sharing the intentionality that also appears in aggressiveness, bullying presents two other characteristics that make it a unique behavior. These include the repetitiveness of the actions and the imbalance of power between the victim and the bully.

Bullying is currently considered a public health problem that affects about one third of students worldwide. Being involved in bullying situations during childhood and adolescence can have serious consequences in different spheres of a person’s life, both short and long term.

It is thus imperative to study the factors associated with bullying behavior to try to understand this phenomenon in its totality. The most recent research indicates that the origin of aggressive behavior is multi-causal and that it is influenced by biological, social, and cultural factors. Although human behavior in general has been studied from a psychosocial point of view, more and a growing body of research is attempting to focus on the study of biological factors. However, few studies have tried to explore the possible biological markers of bullying.

Regarding biological factors that influence behavior, previous research has focused on the role of hormones, specifically testosterone and cortisol, at two developmental periods. The prenatal and pubertal periods are two developmental stages sensitive to the effects that hormones have on the nervous system and therefore on behaviors dependent on brain structures altered by these hormones.

Based on all this, a study of the INMA project decided to explore bullying behavior from a biopsychosocial perspective, taking into account the effects that could have both social psychological variables and hormonal levels of preadolescents. The study was carried out with 302 preadolescents from the INMA project cohort in Gipuzkoa. When the preadolescents were 11 years old, information about bullying behavior was collected using a questionnaire. In addition, information on several psychological and social variables (executive function, family context, school context and social context) was collected by asking these pre-adolescents and their relatives. Data on prenatal and prepubertal hormone levels were determined by saliva samples and the 2D:4D ratio.

The results showed that 9.6% of the participants were involved as victims, 1.7% as bullies and another 1.7% as bullies/victims. The study found that only the bullying role in boys appeared to be influenced by both hormonal levels and psychosocial variables. Specifically, it was observed that lower prepubertal cortisol levels together with a poorer perception of the school environment and lower peer and social group support were associated with a higher risk of being involved in bullying situations as bullies.

The findings of this study are in line with what previous researchers have found in other studies. However, there is still limited evidence on the role of biological factors in bullying. Therefore, the study of bullying should continue to be approached from a biopsychosocial perspective. Identifying the hormonal levels that may affect this behavior, as well as the variables of interest from a more psychosocial aspect, we will be able to better profile those people who are vulnerable to being involved in this type of situation and also to develop bullying prevention and intervention programs in order to reduce its prevalence or the percentage of participants involved.

Reference: Babarro I, Andiarena A, Fano E, García-Baquero G, Lebeña A, Arranz-Freijo EB, Ibarluzea J. Do prepubertal hormones, 2D:4D index and psychosocial context jointly explain 11-year-old preadolescents’ involvement in bullying? Biol Psychol. 2022 Jul;172:108379. doi: 10.1016/j.biopsycho.2022.108379. Epub 2022 Jun 8.

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