2 Theory
2.3 Social factors
2.3.1 Socioeconomic status
The term “socioeconomic status” (SES) traditionally refers to the relative position of an individual, a family, or a group in a stratified social system where certain societal goods (e.g., education, occupation, and economic resources) are not uniformly distributed (Bradley & Bornstein, 2003).
Following the Bioecological Model of Development, the family is the most important microsystem. Children belonging to different socioeconomic strata will experience different proximal processes because the characteristics of their family, both social and physical, differ across these strata.
2.3.1.1 Measuring socioeconomic status
It has been argued that education indexes human capital, income indexes financial capital, and occupation indexes social capital (Conger &
Dogan, 2007). Educational, financial, and occupational factors all work to create SES-related differences in parents’ circumstances and characteristics that will affect various developmental outcomes (Conger
& Dogan, 2007; G. J. Duncan & Magnuson, 2003).
Maternal education is used as an indicator of SES in the present thesis, and it is in fact the most commonly used single indicator of SES in child-development research (Ensminger & Fothergill, 2003). This is due in part to ease of data collection and to reliability of data (Hoff, Laursen, &
Bridges, 2012), but also to the instability of other SES components:
parental occupation and income may fluctuate throughout an individual’s childhood, but his or her parents’ level of education tends to be relatively stable (G. J. Duncan & Magnuson, 2003).
Parenting behavior is more strongly influenced by education than by income or occupation, and empirical findings have shown that maternal
Theory
education is the best single indicator of SES in predicting child outcomes (Bornstein, Hahn, Suwalsky, & Haynes, 2003; Hoff et al., 2012).
Maternal education is interpreted as reflecting a process in which parenting behavior (e.g., style and practice) mediates the effect of SES on development (e.g., Hoff et al., 2012).
Moreover, previous research has found the correlation between income and education to be weaker in Norway than in other Western countries (Barth, 2005). One reason for this may be that Norway is a rich oil-producing country where, in recent years, being highly educated has not been a prerequisite for a well-paid job (Størksen et al., 2015).
Considering these research findings, maternal education is particularly well suited as a sole indicator of SES in studies investigating child development and in studies conducted in countries such as Norway, with a well-functioning welfare system and relative economic parity as compared with countries such as the United States.
2.3.1.2 Socioeconomic status and children’s academic skills and self-regulation
There is a large body of evidence linking parental SES to many aspects of child development. Studies have found associations between SES and brain structure (Noble et al., 2015), cognitive development and intellectual functioning (Eilertsen et al., 2016; Hoff, 2003), academic achievement (Bakken & Elstad, 2012; Sirin, 2005), self-regulation (Montroy, Bowles, Skibbe, McClelland, & Morrison, 2016; Størksen et al., 2015), and mental health (Bøe, Øverland, Lundervold, & Hysing, 2012). The present thesis investigated associations between SES and children’s vocabulary and mathematical skills in Study I and between SES and self-regulation in Study III. Moreover, Study II controlled for SES to account for variation in the home environment. More detailed overviews of prior findings with regard to SES differences in academic skills and self-regulation are provided in Studies I and III. In the
Theory
following, perspectives and theory related to mechanisms underlying SES differences in child development are addressed.
SES and child development are both multifaceted variables, and many factors that have been found to influence child development covary with SES. Hence it may be a challenging task to uncover the causal relations underlying the effects of SES on child development (Hoff, 2003). Two main mechanisms have been suggested when it comes to explaining the association between SES, social processes, and individual development:
social causation and social selection (Conger & Donnellan, 2007).
According to the social-causation perspective, social and economic conditions influence individual functioning and development. Two approaches consistent with this perspective are the Family Stress Model (FSM) and the Investment Model (IM). The FSM links socioeconomic disadvantage (i.e., poverty) to a family-stress process that increases parents’ emotional distress and jeopardizes the healthy development of their children (Yeung, Linver, & Brooks–Gunn, 2002). An environment that has fewer resources and is less predictable may cause attention systems, emotional systems, and biological stress systems to become more reactive, which is less conducive to the development of EF abilities and self-regulation (Blair & Ursache, 2011). In contrast, environments that are high resources and where appropriate support is provided may cause attention systems, emotional systems, and biological stress systems to develop in ways that promote EF and self-regulation.
The IM is rooted in economic principles of investment but has been extended to include social and human capital. It builds on the notion that higher-SES parents have better access than lower-SES parents to financial (e.g., income), social (e.g., occupational status), and human (e.g., education) capital. Families’ investments of such capital are associated with positive child development. It has been found that family-stress processes better predict behavioral problems, whereas parental investments—which are more relevant than family-stress
Theory
processes when maternal education is the indicator of SES—better predict cognitive development (Kalil & Ryan, 2020; Yeung et al., 2002).
According to the social-selection perspective, the associations observed between parental SES and child development are spurious because they are caused by a third variable (Conger & Donnellan, 2007). This third variable may be parental intelligence and personality, in which case it is thus hypothesized that both parental SES and children’s development emanate from such parental characteristics.
Conger and Donnellan (2007) conclude that there is empirical support both for the social-causation perspective and for the social-selection one, arguing that the tension between these two views on the relationship between SES and human development is redolent of the nature–nurture debate and that neither view is likely to reflect the complexity of human development. Instead, they suggest a comprehensive model—the
“interactionist perspective”—that incorporates both perspectives alongside child characteristics. This comprehensive model aligns well with the Bioecological Model of Development (Bronfenbrenner &
Morris, 2006), which encompasses both the biological realities of the individual and the characteristics of the family (microsystem). In addition to this, however, the Bioecological Model of Development also includes other social contexts such as ECEC (microsystem), and it takes account of how the ideology and organization of the relevant society (macrosystem) influence the proximal processes in the microsystems (e.g., the effect of SES on child outcomes).
Several studies have investigated the associations between parental SES and child development. Bradley and Corwyn (2003) found parental education to be positively related to children’s vocabulary, reading, and mathematical skills as well as negatively related to behavioral problems, even when several other variables were controlled for. In addition, they found that parental stimulation of learning partly mediated the relationship between parental education and child competence.
Theory
Compared with lower-SES parents (including in terms of maternal education), higher-SES parents are more likely to use a rich vocabulary and to engage in cognitively stimulating activities with their children (Hart & Risley, 1995; Hoff, 2003). Likewise, higher-SES parents tend to engage in complex mathematical interactions with their children more often than parents with a lower SES (Saxe, Guberman, & Gearhart, 1987). The above-mentioned studies show that SES-related differences in children’s outcomes can be associated with SES-related differences in their experiences and proximal processes.
In summary, research suggests that parents with higher SES are likely to invest their resources and behave in ways that facilitate their children’s development in terms of vocabulary, mathematical skills, and self-regulation.