Respiratory sinus arrhythmia (RSA) represents a rhythmic variation in heart rate synchronized with breathing, serving as a marker of autonomic regulation and psychophysical well-being. In children, RSA is particularly pronounced, reflecting greater vagal flexibility and an enhanced ability to adapt to internal and external stimuli. However, factors such as poor posture, sedentary behavior, and modern social pressures are progressively compromising thoracic compliance, interfering with diaphragmatic breathing and reducing the effectiveness of RSA. This article explores the connection between bodily dysmorphisms, emotional regulation mediated by vagal tone, and social pressures, highlighting how these factors negatively affect physiological development and the psychophysical well-being of children. Preventive strategies and targeted interventions are proposed to promote a balance between autonomic regulation and emotional resilience, supporting healthy development within a social and evolutionary context.