When a child loses in a competitive activity, emotions such as frustration, anger, sadness, or helplessness are often triggered. These emotional responses, explains Júlia Maria Bonet, a child and adolescent clinical psychologist, have a neurobiological basis, since the brain is still developing the structures responsible for emotional regulation, such as the prefrontal cortex. Furthermore, Bonet continues, their self-esteem is still highly dependent on external success, and they may perceive defeat "as a threat to their personal worth." Bonet emphasizes that, according to Bandura's self-efficacy theory, which stipulates that self-confidence influences behavior and success, "if children have not developed sufficient confidence in their abilities, they may experience defeat as a deeply personal failure."

Aggressive play is uncomfortable. The fear that by allowing it, we are encouraging violent behavior is very common. Rejecting this play is equivalent to denying a natural need for expression.