GBG has demonstrated a wide range of positive outcomes through rigorous research. In the short term, it improves classroom behaviour by increasing time-on-task, reducing disruptions, and creating a more supportive learning environment. It also enhances students' social-emotional skills and peer relationships, promoting cooperation and self-regulation. In the long term, GBG has been shown to significantly reduce aggressive and disruptive behaviour, lower the risk of substance use, smoking, and alcohol abuse, and decrease antisocial, criminal, and violent behaviours—particularly among high-risk students. It also reduces depressive symptoms and suicidal ideation and overall well-being into adolescence and young adulthood.

The mechanism of action is getting the children to internalise behaviour self-regulation. This strengthens the pathways connecting their Amygdala, Prefrontal Cortex, and Hippocampus.  The hippocampus-PFC (prefrontal cortex)-amygdala axis plays a crucial role in behaviour self-regulation by integrating emotional processing from the amygdala, cognitive control from the PFC, and contextual memory from the hippocampus. The axis allows individuals to manage their responses to stimuli and situations, particularly when dealing with emotionally charged experiences; it essentially acts as a system to 'think before you act’.

The GBG is considered a low-risk intervention. The studies we have reviewed do not report significant risks of psychological or social harm, but emphasize on teacher training to ensure fair implementation.