Association of Maternal Social Relationships With Cognitive Development in Early Childhood

This cohort study of mother-child pairs from Tennessee investigates whether variations in maternal social networks are associated with cognitive development in children.


Introduction
Social networks, broadly defined as interconnectedness with other people, can influence behavioral and health outcomes. [1][2][3] The importance of social and relational environments for cognitive development and emotional well-being is well known. 4-8 Networks of social support can attenuate psychologic stress and provide support to people experiencing neurotic symptoms. [9][10][11][12] The progress that children make when forming healthy relationships during the period from birth to 5 years can have long-lasting benefits throughout their entire lives. 13 In early childhood development, relationships between children and caregivers are crucial and play an important role in socialization. [14][15][16][17] The social environment and relationships early in life are critical for children's emotional, intellectual, and social development into adulthood and can considerably influence the child's life-long adaptation strategy. 6,13,18-21 Social networks channel benefits and risks associated with social health determinants, such as health-related knowledge, attitudes, and capacity to cope with adversities associated with social disadvantage. 1,4,6,[22][23][24] The network microsystem has been regarded as a critical domain for child development. 6,15 Children's early experience of relationships can influence a wide range of developmental outcomes, 7,15,25 and the child-mother relationship is important in shaping early childhood development. 17,21,26,27 From the child's perspective, these intimate bonds form the basis for solid attachments and provide prototypes for adulthood and the basis for social interaction. 15,28-31 The child-mother relationship is not the only determinant but is nested within larger social contexts. The father plays a significant role in children's development, 17,25,[32][33][34][35] as do the number of siblings and household size. 36,37 Social support, along with other aspects of the social networks surrounding the child-mother bond, can influence the child-mother relationship. 38,39 For mothers, social support is significantly associated with lower maternal stress, which is correlated with better child development. [40][41][42][43] Little is known about how different types of relationships, especially the multiple social networks of the mother, are associated with children's cognitive development. Only a few studies 8, 43 have characterized a range of maternal social networks and examined their association with early childhood cognitive development. In this study, we examined the associations of multiple types of social relationships and structures, including the child-mother-father triad, family setting, and larger neighborhood network conditions, with early cognitive development. Within a large group of white and African American families in Memphis and Shelby County, Tennessee, we examined how social relationships and networks were associated with children's cognitive development.

Data Source
This study followed Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guideline. 44  Because of the availability of extensive information about child-mother relationships and their contexts in the CANDLE study, we systematically examined multiple layers of networks and their association with cognitive development in early childhood.
The framework of the stepwise network structures is presented in the Figure. We studied 4 network conditions: father's cohabitation (triad), large family network (family), mother's social support network (caregiver's social support network), and neighborhood. Family network size was estimated using data on household size, including all adults and other children living with the child involved in the CANDLE study. The mean (SD) of the household size variable was 4.37 (1.51) people, and we defined a family of 6 or more as a large family network. The primary caregiver's social network was defined by the mother's self-reported social support network. The mothers participating in CANDLE reported 3 to 4 people they could rely on for help, with a mean (SD) of 3.49 (1.82) people.
We also included an indicator variable that asked mothers if they knew many people in their neighborhood.

Statistical Analysis
We used multivariate robust regression models to study the associations of multiple social networks and cognitive development of 2-year-old children. To minimize the influence of outliers, we used robust regression methods. 48 This approach allowed us to investigate how multiple layers of social network conditions are associated with cognitive development in early childhood. A 2-sided P Յ .05 was set a priori to represent a statistically significant difference. We used Stata, version 14 (StataCorp) for statistical analysis.
We adjusted for several maternal and socioeconomic characteristics in a stepwise fashion. The first step included network variables. 32 We included the following factors as independent variables in the model because of potential confounding: mother's IQ, child's birth weight, mother's age, and father's educational level. We originally tested other possible confounders, such as child sex, gestational age at birth, breastfeeding, birth weight, maternal smoking, and mother's educational level. However, they were not included in the model because they did not substantively influence the coefficient of the main variables. The second model was adjusted for the same variables as the main model, but family poverty level was added. 49  The solid line between mother and child represents a tie that is always present, as in this study because children were recruited through their mother; dashed lines represent ties that may or may not exist.

Discussion
The importance of the mother-child bond for child development has long been recognized. 17,21,26,27 However, to our knowledge, the multiple layers of a mother's social relationships beyond mother and child have not been simultaneously examined. Social relationships do not exist in isolation, and mother-child relationships are intertwined with other relationships, such as spouses, family or dwelling settings, and friendships. Our empirical analysis simultaneously investigated the association of multiple layers of the mothers' social networks with children's early cognitive development. Most social contacts and contexts of young children were determined by their primary caregiver's social networks, who were often mothers in the CANDLE cohort.
In this study, we showed that a primary caregiver's network conditions were significantly associated with early cognitive development in children. Network variables were significantly associated with early cognitive development after controlling for a number of biological and social confounders. Specifically, the mother's social network seemed to have a beneficial association with the cognitive development of children, whereas family size had a negative association. Although father's cohabitation has been suggested to be an important factor for early childhood cognitive development, 17,34,58 after controlling for other social network conditions of the mother and other possible confounders, we did not find evidence for this result in our study. This might be because of the local context-Memphis is an economically disadvantaged area of the United States, which might mitigate an otherwise positive association of father's cohabitation.
Many of our findings are consistent with previous studies 36,37,59 of early cognitive development and add important evidence that social networks across several levels may be significantly associated with cognitive development in early childhood. Being raised in a large family (Ն6 people) was significantly associated with lower cognitive performance, a finding that is also in line with previous studies of large families. 36,37 However, past studies have also shown that family size can have advantages (ie, positive socialization) and disadvantages (ie, resource competition or limitation). 59 Our findings about the negative association of family size may have been attributable to the limited attention and resources that a child received from the primary caregiver when faced with competing demands. Further investigation is needed to identify the mechanisms of this disadvantage.
We also reported results that large maternal social networks were positively associated with the cognitive development of children. Children of mothers who knew many people in the neighborhood had better cognitive development. It is possible that mothers who socialized locally provided children with more opportunities for playdates with other children or stimulation through more social activities. In addition, the primary caregiver's social networks within the neighborhood may have buffered the association between reduced economic resources and child outcomes. 60 Our results captured the importance of a community-based social life.

Limitations
Our study has a number of limitations. We did not have information on relationship quality. Our measure of neighborhood embeddedness was based on subjective perception self-report. In addition, we only looked at relational embeddedness, not the physical or built neighborhood environment. Further research is needed to examine the nature of the association between neighborhood embeddedness, both physical and relational, and cognitive development in early childhood.

Conclusions
The findings suggest that social relationships beyond the mother-child-father triad are significantly associated with children's cognitive development and that maternal social relationships may be associated with the cognitive development of children.