Emotion-related self-regulation in children is closely linked to their development and is associated with maladjustment. Effortful self-regulation, which involves voluntary control, develops rapidly in early life and improves more slowly into adulthood. Individual differences in self-regulation are stable after the first two years and are inversely related to externalizing problems. While findings on internalizing problems are less consistent, emotion-related self-regulation is inversely related to internalizing problems after early childhood. Self-regulation is influenced by genetic and environmental factors and their interactions. Interventions aimed at improving self-regulation can reduce maladjustment. Emotion regulation involves processes that manage and change how emotions are experienced and expressed. It includes situation selection, attention deployment, cognitive change, and response modulation. Effortful control, a key component of self-regulation, involves inhibitory control, activation control, and executive functioning. It is linked to the anterior cingulate gyrus and prefrontal cortex. Effortful control is distinct from reactive control, which is more automatic and less voluntary. Reactive control includes impulsive undercontrol and rigid overcontrol, which are associated with different aspects of temperament. The development of emotion regulation begins in infancy, with children learning to regulate their emotions through self-soothing behaviors and attentional control. Effortful control improves with age, involving better attentional focus, inhibitory control, and planning. Executive functioning skills, such as delaying gratification, also develop over time. Studies show that children with higher effortful control have fewer externalizing problems, such as aggression and defiance. Effortful control is inversely related to internalizing problems, though the relationship is less consistent. Stability in effortful control is evident from early childhood to adolescence, with consistent findings across different age groups. Effortful control is associated with better adjustment and is influenced by both genetic and environmental factors. Research indicates that children with higher effortful control have lower levels of externalizing and internalizing problems. Physiological measures, such as cardiac vagal regulation, also support the role of self-regulation in maladjustment. Children with higher vagal suppression are more vulnerable to externalizing problems, while moderate levels are adaptive. Effortful control is crucial for managing internalizing problems, such as anxiety and depression. Children with internalizing problems may exhibit overcontrol, but this is not volitional. Effortful control helps regulate attention and emotion, reducing bias toward negative stimuli and improving social interactions. Inhibitory control is less directly related to internalizing problems than other components of effortful control. However, children with comorbid internalizing and externalizing problems may have lower inhibitory control. Overall, effortful self-regulation is a key factor in children's adjustment, with strong negative associations to externalizing and internalizing problems. Interventions that enhance self-regulation can improve children's behavior and emotional well-being.Emotion-related self-regulation in children is closely linked to their development and is associated with maladjustment. Effortful self-regulation, which involves voluntary control, develops rapidly in early life and improves more slowly into adulthood. Individual differences in self-regulation are stable after the first two years and are inversely related to externalizing problems. While findings on internalizing problems are less consistent, emotion-related self-regulation is inversely related to internalizing problems after early childhood. Self-regulation is influenced by genetic and environmental factors and their interactions. Interventions aimed at improving self-regulation can reduce maladjustment. Emotion regulation involves processes that manage and change how emotions are experienced and expressed. It includes situation selection, attention deployment, cognitive change, and response modulation. Effortful control, a key component of self-regulation, involves inhibitory control, activation control, and executive functioning. It is linked to the anterior cingulate gyrus and prefrontal cortex. Effortful control is distinct from reactive control, which is more automatic and less voluntary. Reactive control includes impulsive undercontrol and rigid overcontrol, which are associated with different aspects of temperament. The development of emotion regulation begins in infancy, with children learning to regulate their emotions through self-soothing behaviors and attentional control. Effortful control improves with age, involving better attentional focus, inhibitory control, and planning. Executive functioning skills, such as delaying gratification, also develop over time. Studies show that children with higher effortful control have fewer externalizing problems, such as aggression and defiance. Effortful control is inversely related to internalizing problems, though the relationship is less consistent. Stability in effortful control is evident from early childhood to adolescence, with consistent findings across different age groups. Effortful control is associated with better adjustment and is influenced by both genetic and environmental factors. Research indicates that children with higher effortful control have lower levels of externalizing and internalizing problems. Physiological measures, such as cardiac vagal regulation, also support the role of self-regulation in maladjustment. Children with higher vagal suppression are more vulnerable to externalizing problems, while moderate levels are adaptive. Effortful control is crucial for managing internalizing problems, such as anxiety and depression. Children with internalizing problems may exhibit overcontrol, but this is not volitional. Effortful control helps regulate attention and emotion, reducing bias toward negative stimuli and improving social interactions. Inhibitory control is less directly related to internalizing problems than other components of effortful control. However, children with comorbid internalizing and externalizing problems may have lower inhibitory control. Overall, effortful self-regulation is a key factor in children's adjustment, with strong negative associations to externalizing and internalizing problems. Interventions that enhance self-regulation can improve children's behavior and emotional well-being.