Theorists and researchers who emphasize the role of nature in development believe that every child is born with a set of personality characteristics that Thomas and Chess (1977) call temperament. These characteristics play an important role in shaping the responses of a child’s caregivers and, ultimately, in molding the child’s future personality. There has been enormous interest in temperament since researchers first studied it in the 1920s. Since those early investigations, the concept of temperament has evolved. For example, Thomas and Chess originally identified nine dimensions of temperament. Because their dimensions were not independent, other researchers combined them into three dimensions. Sanson, Hemphill, and Smart (2002) call the first dimension negative emotionality, and include irritability, negative mood, inflexibility, and high intensity as negative reactions. Self-regulation is the second dimension, and includes persistence, nondistractibility, and emotional control. The third dimension, approach/withdrawal, inhibition, or sociability includes both approaching new situations and people or withdrawing from them.

These attributes of temperament combine to characterize differences between children and how they respond to their caregivers (Thomas & Chess, 1977). The easy child, for example, is very adaptable, playful, and responsive to adults. This type of child is likely to receive a great deal of adult attention during the early years because interactions are so pleasant and reinforcing. The difficult child, on the other hand, provides little positive feedback to adults. He is fussy, difficult to soothe, and has problems sleeping and eating. Finally, the temperament of the slow-to-warm-up child is characterized by slow adaptability. Adults who sustain contact with this type of child are usually rewarded by the positive behaviors found in the easy child, but it takes considerably longer to elicit them.

Although there is some evidence that temperament is stable over time, there are some factors that affect some types of temperament. Martin and Fox (2006) suggest that these factors include the sex of the child (e.g., inhibited girls are more likely to change than inhibited boys), children’s participation in out-of-the-home care (e.g., children who receive outside child care become less inhibited over time), and parental characteristics (e.g., parents who are overcontrolling have children who remain inhibited over time). Limited research has examined the role of cultural differences on temperament; this research largely has been conducted with older children (Sanson et al., 2002).


One of the more widely reported gender differences in social and emotional development is that boys exhibit more aggression than girls. Although there seems to be little difference in the rate of aggression in infancy, by the time children enter preschool, boys engage in more conflict and in more verbally and physically aggressive acts than girls. According to Underwood (2002), this gender difference holds across socioeconomic groups and across cultures. Males tend to be more vulnerable to family and life stresses than females (Patterson, DeBaryshe, & Ramsey, 2000). It has been postulated, however, that males are reinforced for more aggressive and competitive behavior by family members and peers, which accounts for increasing differences in their social patterns as they develop (Coie & Jacobs, 2000).

Although the rate of overt aggression is much higher among boys, relational aggression is higher among girls. Relational aggression “harms others through manipulation or control of relationships” (Crick, 2000, p. 310). Crick and her colleagues designed teacher and peer rating scales to measure relational aggression in preschool children. Behaviors that reflected relational aggression included not inviting a classmate or peer to a birthday party, not letting a peer play in the group, and not listening to a peer or other person because of feelings of anger toward that individual. These behaviors contrasted with those that reflected overt aggression such as pushing and shoving and throwing objects at others in response to frustration. Crick and her colleagues found that teachers particularly rated preschool-aged girls as more relationally aggressive and less overtly aggressive than preschool-aged boys. They also found that children who showed either type of aggression were rejected by their peers more often than those who were not aggressive.


The formation of a child’s personality is closely related to the types of stress to which he is subjected in his early years and to how he deals with that stress. A child who lives in poverty, has multiple hospital stays, or comes from a dysfunctional home is at risk for long-lasting psychosocial disorder. Still, some resilient children handle stress better than others do and many progress through adverse early years relatively undamaged (Masten & Gerwitz, 2006). Those resilient children benefit from adults in both their family and their community who are competent and caring (Masten, 2001).

Sibling Relationships

Researchers have speculated that children’s social interactions with peers are affected by the relationships they have with their siblings. This makes intuitive sense for a number of reasons. First, children spend a lot of time with siblings—more time than they spend with either their parents or, when they are young, with their peers. Second, siblings give children the opportunity to practice social skills. They have the opportunity to engage in positive social exchanges and to resolve conflict with partners who, unlike parents, have a similar level of sophistication. Although researchers have hypothesized that there is a link between children’s interactions with siblings and with peers, little empirical evidence for that link exists (Dunn, 2002).

There is particularly limited research on the nature of sibling relationships in minority communities and in non-Western cultures (Dunn, 2002). The nature of sibling relationships outside of the United States may differ because, in a number of cultures, siblings often function as caregivers from an early age and may serve to socialize children for parenthood (Dunn, 2002).

Parental Style

Baumrind (1973) speculated that parents’ style of interacting with their child would have an impact on that child’s later development. He described parents as authoritative, authoritarian, or permissive.

The authoritative parent is firm and willing to set limits, but not intrusive. Authoritative parents encourage their children to explore their environments and gain interpersonal competence. In contrast, the authoritarian parent is harsh, rigid, and unresponsive to her child. The third type of parent, the permissive parent, is affectionate toward her child but lax and inconsistent with her discipline. As a consequence, her child is uncontrolled and may show impulsive behavior (Parke & Buriel, 1998).

Parke and Buriel (1998) found a number of problems with Baumrind’s conceptualization of parental style. First, a distinction can be drawn between style (or parental attitudes) and parental practices. Second, as noted by Sameroff and his colleagues (Sameroff & Chandler, 1975; Sameroff & Fiese, 1990), the direction of effects is as likely to be from the child to the parent as the reverse. Finally, the scheme may not be universal. It may not apply to parents from different socioeconomic backgrounds or to parents from diverse cultures. For example, Russell, Mize, and Bissaker (2002) note that some research has shown that, in African American families, harsh discipline co-exists with warm and nurturing relationships more often than in white families.

According to Parke et al. (2002), parents do indeed affect their children’s social and emotional development through three different routes: (1) they interact directly with their children; (2) they instruct, teaching their children about what constitutes important social behavior; and (3) they provide their children with opportunities for social experiences.

Parke et al. (2002) assert that children’s social relationships extend beyond the immediate family to the extended family, the neighborhood and school, and places of worship. Because children have so many chances to interact with others and form relationships, parents can enhance children’s relationships by actively managing these opportunities. For example, parents can supervise their children’s choice of activities and friends, they can initiate and arrange play dates for their children, and they can enroll their child in organized activities like religious (pre)school.

Both mothers and fathers influence children’s social and emotional development. Research does not make clear whether the relationships that children have with mothers and fathers is more similar than different; however, there is some evidence that interaction with fathers is more often focused on play and recreation, while interactions with mothers tend to revolve around caregiving (Russell et al., 2002).