The role of maternal education and nonmaternal care services in the prevention of children's physical aggression problems

CONTEXT

Physical violence is an important health problem, and low maternal education is a significant risk for the development of chronic physical aggression (PA). We hypothesized that nonmaternal care (NMC) services could prevent the development of childhood PA problems, depending on the age at which the services are initiated. Method Children who followed a trajectory of atypically frequent PA between 17 and 60 months of age among a population sample of 1691 Canadian families were identified. Maternal education and NMC were considered in predicting group membership while controlling for confounding family characteristics.

RESULTS

Children of mothers with low education levels (ie, no high school diploma) were less likely to receive NMC. Those who did receive such care had significantly lower risk of a high PA trajectory. Results from logistic regressions indicated that NMC reduced the risk of high PA, especially when initiated before age 9 months (odds ratio, 0.20; 95% confidence interval, 0.05-0.90). Children of mothers who graduated from high school were less at risk of PA problems, and NMC had no additional protective effect.

CONCLUSIONS

Nonmaternal care services to children of mothers with low levels of education could substantially reduce their risk of chronic PA, especially if provided soon after birth. Because children most likely to benefit from NMC services are less likely to receive them, special measures encouraging the use of NMC services among high-risk families are needed.

The joint development of physical and indirect aggression: Predictors of continuity and change during childhood

A person-oriented approach was adopted to examine joint developmental trajectories of physical and indirect aggression. Participants were 1183 children aged 2 years at the initial assessment and followed over 6 years. Most children followed either low or declining trajectories of physical aggression (PA), but 14.6% followed high stable trajectories. Approximately two-thirds of participants followed low indirect aggression (IA) trajectories (67.9%), and one-third (32.1%) followed high rising trajectories. The results combining both PA and IA group memberships indicate that most children (62.1%) exhibit desisting levels of PA and low levels of IA. A significant proportion followed a trajectory of moderately desisting PA and rising IA (14.2%), and 13.5% followed high level trajectories of both forms of aggression. Virtually no children were high on one type and low on the other. Multinomial regressions analyses were used to predict joint trajectory group membership from selected child and family variables measured at 2 years. Young motherhood and low income predicted membership in the high PA-high IA trajectory, but only hostile parenting remained significant after family processes variables were entered in the model. Being a boy, young motherhood, and hostile parenting were generally associated with higher levels of PA. Girls were more likely than boys to follow a trajectory of desisting PA and rising IA. The results suggest that some children, mostly girls, reduce their use of PA and tend to increase their use of IA, and that highly physically aggressive children also tend to be highly indirectly aggressive. Early family risk characteristics and hostile parenting interfere with the socialization of aggression.

Association between nonmaternal care in the first year of life and children's receptive language skills prior to school entry: the moderating role of socioeconomic status

BACKGROUND

Studies have suggested that nonmaternal care (NMC) may either carry risks or be beneficial for children's language development. However, few tested the possibility that NMC may be more or less protective for children with different family backgrounds. This study investigates the role of the family environment, as reflected in the socioeconomic status (SES), in the association between NMC in the first year of life and children's receptive language skills prior to school entry.

METHOD

A representative sample of 2,297 Canadian children aged between 0 and 11 months at their first assessment was followed over 4 years. Receptive language skills were assessed with the Peabody Picture Vocabulary Test Revised (PPVT-R) when the child was 4 to 5 years old.

RESULTS

After controlling for selection factors, SES was found to moderate the association between NMC and receptive language skills: Full-time NMC in the first year of life was associated with higher PPVT-R scores among children from low SES families (d = .58), but not among children from adequate SES families.

CONCLUSION

Full-time NMC in infancy may contribute to reducing the cognitive inequalities between children of low and adequate SES.

The development of physical aggression from toddlerhood to pre-adolescence: a nation wide longitudinal study of Canadian children

The objectives of the study were to model the developmental trajectories of physical aggression (PA) from toddlerhood to pre-adolescence and to identify risk factors that distinguish typical (normative) from atypical developmental patterns. Ten cohorts of approximately 1,000 children (n = 10,658) drawn form a nationally representative (Canadian) sample were followed over 6 years. Using a group based trajectory approach, we identified three groups of children with distinct developmental trajectories between 2 and 11 years of age. One third of the children (31.1%) followed a low desisting trajectory, reflected in infrequent use of PA in toddlerhood and virtually no PA by pre-adolescence. The majority of children (52.2%) followed a moderate desisting trajectory, reflected in occasional use of PA in toddlerhood and infrequent use by pre-adolescence. One sixth of the children (16.6%) followed a high stable trajectory of PA. Multivariate logistic regression indicated that children in the high PA trajectory group were more likely to be boys (OR: 1.67; CI: 1.5-1.87), from low income families (OR: 1.4; CI; 1.27-1.67), from families where the mother had not completed high school (OR: 1.20; CI: 1.05-1.38) and who reported using hostile/ineffective parenting strategies (OR: 1.16; CI: 1.14-1.18). In sum, the results indicate that the typical developmental pattern of PA was one of occasional and declining use over time. However, about one sixth of children, mostly boys from disadvantaged families, exhibited an atypical developmental pattern reflected in more frequent and stable use of PA. The results suggest that most children learned relatively well to inhibit PA by the end of childhood and that a minority failed to do so. Family risks traditionally found to be associated with antisocial behaviors during adolescence appear to interfere with the socialization of PA during early and middle childhood.

Daycare attendance, stress, and mental health

OBJECTIVE

Daycare stress can be indexed by cortisol, and elevated levels of cortisol have been implicated in the onset and development of mental health disorders. Our objective was to quantify the associations between daycare and cortisol and to identify individual and environmental conditions under which daycare attendance is associated with cortisol concentrations.

METHODS

We used Cohen effect size statistics to quantify these associations and to compare them across 11 published studies that were identified with MEDLINE and PsycINFO.

RESULTS

Cortisol levels increased during the daycare day, whereas they decreased when children stayed at home. The mean effect size was d = 0.72. The magnitude of the daycare-stress relation seemed to vary under 3 specific conditions. First, the effect size was larger for children in low-quality daycare (d = 1.15), whereas there was essentially little or no effect for children in high-quality daycare (d = 0.10). Second, the effect size was larger for preschoolers (aged 39 to 59 months) (d = 1.17) than for infants (aged 3 to 16 months) (d = 0.11) or school-aged children (aged 84 to 106 months) (d = 0.09). Third, children with difficult temperaments in daycare were more likely to exhibit a rising pattern of cortisol, compared with children who were not difficult.

CONCLUSIONS

Our review suggests that daycare attendance in relatively low-quality daycare conditions and for children with difficult temperaments may result in atypical cortisol elevation. Although the link between atypical cortisol elevation and mental health requires further study, programs aimed at improving the quality of daycare services during the preschool years are expected to lead to better physiological adaptation to daycare and to reduce the risks of mental health problems.