Origins of trait shyness. As a relatively stable personality characteristic, one important issue is how trait shyness develops. Research and theory suggests two major sources of trait shyness (Buss 1984). First, trait shyness often reflects a genetic predisposition toward inhibition and excessive anxiety. Several studies have found evidence of a high degree of inheritablity for shyness (e.g., Plomin and Rowe 1979). Alternatively, shyness may emerge because of disruptions or problems in development, most especially those involved in the establishment of a personal identity during adolescence (e.g., Asendorpf 1989; Buss 1984).
Social inhibition is a developmental precursor of shyness and is relatively stable over time (Kagan, Reznick, and Snidman 1988). Inhibition in an infant is often manifested as stranger anxiety, which is common at about nine months of age. Not all infants are excessively afraid of strangers, and even those who are often become much less so during the second year. For a minority, however, inhibition continues and resembles the avoidant and reticent behavior of shy adults. Children with a chronically inhibited social interaction style beyond age three are usually labeled as shy. Thus, the idea that some children are born with the biological foundation for shyness is further supported by research showing that inhibition is consistent across situations and is related to specific physiological responses: Shy-inhibited children tend to have higher and less variable heart rates and larger pupil dilation during cognitive tasks than uninhibited children (Garcia-Coll, Kagan, and Reznick 1984).
Alternatively, shy children may be conditioned for inhibition by parents or others (Asendorpf 1989). For example, being intimidated, harassed, or rejected may encourage a wariness of others as a means of avoiding being hurt. This is especially so if shy expressions are also modeled or reinforced by parents. More commonly, uncertainty and anxiety associated with establishing a personal identity in adolescence may initiate shyness (Buss 1984). The transition from elementary to secondary school, the relative increase in peer influence as compared to parental/family influences, and accommodation to social and role expectations are illustrative of the identity transformations that may be implicated in the initiation of acquired shyness. Consequently, although some children may be born with a readiness for inhibition and physiological arousal in social situations, this inclination may at least partially actualize through environmental/developmental factors involving both learning and stress.
On the other hand, in one study shyness at age two predicted parenting practices at age four such as a lack of encouragement of independence, but parenting practices at age two did not predict shyness at age four (Rubin et al. 1999). This suggests that the experiential contribution to the development of shyness may be a parental response to existing shyness rather than shyness resulting from differences in parenting behaviors.
Developmental manifestations of trait shyness. Another important issue regarding trait shyness is how it is expressed at various stages in the life cycle. Being shy during childhood does not automatically mean that an individual will remain shy throughout life. On the other hand, shyness appears to stabilize by approximately eighth or ninth grade, and adolescent shyness has been found to predict significantly adult shyness as much as twenty-five years later (Morris, Soroker, and Burruss 1954). During adolescence, shyness is likely to be intensified by the physical impact of puberty as well as changes in social context in the adolescent's life that may contribute to disturbances in self-image. In this regard, junior high school students more frequently describe themselves as shy than do elementary school students (Simmons and Rosenberg 1975).
Shyness among adults involves inhibited social behavior that impedes the development of friendships and romantic and work relationships ( Jones and Carpenter 1986). For example, shy adults tend to have selective memory for unpleasant social interactions, underestimate their own social skill, and assume responsibility for failure, but not for success (Halford and Foddy 1982; Jones and Briggs 1984; Jones and Carpenter 1986). Also, shy adults are less effective in asking for help, expressing opinions, and coping with stress, and more likely to engage in negative self-evaluations (DePaulo et al. 1989; Eisenberg, Fabes, and Murphy 1995; Jones, Briggs, and Smith 1986).
Longitudinal data indicates that individuals identified as shy and reserved in late childhood differed in marital and family experiences thirty years later (Caspi, Elder, and Bem 1988). For example, shy males were more likely than their male age cohorts to delay marriage and parenthood to a later point in life, whereas shy girls were more likely to pursue conventional marital, childbearing, and homemaking endeavors than their less shy counterparts.
In work-related situations, chronically shy persons tend to achieve lower occupational status and stability (Caspi, Elder, and Bem 1988). Also, shy adults fail to take advantage of the employment opportunities available to them and are less confident and active in occupational endeavors (Phillips and Bruch 1988). For elderly adults, shyness is associated with greater life disruption as a result of retirement, widowhood, and other changes toward the end of the life cycle (Hansson 1986). However, because the social roles of the elderly have fewer effects on other people and the evaluations of others are not as important to the elderly, shyness may have fewer or less dramatic consequences as people grow older.