SurgencyExtraversion

Surgency/extraversion, commonly referred to as Surgency/Extraversion (SE), is a temperament dimension in child development theory. It encompasses traits such as high activity level, rapid approach to new people and objects, high-intensity positive affect, sociability, and impulsivity. In Rothbart's model of temperament, SE forms one of three core dimensions—alongside Negative Affectivity and Effortful Control—reflecting early patterns of reactivity and self-regulation that can influence behavior across development. In adulthood, the construct is related to, but not identical with, the broader personality trait of extraversion.

SE is typically assessed through parent- or caregiver-reported inventories like the Infant Behavior Questionnaire and the Children's Behavior Questionnaire. Some studies employ observational paradigms that involve approaching unfamiliar stimuli, play with toys, or social interactions. Components are often organized into subareas such as Activity Level, Approach/Positive Anticipation, and Positive Expressivity.

Development and outcomes: SE can be observed in infancy and tends to show moderate stability into childhood and beyond, though environmental context and parenting influence its expression. Higher SE is associated with more sociable play, enthusiasm, and willingness to engage with novelty; when paired with weaker regulatory skills, it may relate to externalizing problems, impulsivity, or risk-taking. Lower SE is linked to caution, fearfulness, or withdrawal.

Relationship to related concepts: SE is distinct from the Big Five extraversion, though overlapping constructs exist; SE emphasizes temperament and early reactivity rather than long-term personality structure. Cross-cultural variation exists in how high activity and sociability are expressed and interpreted.