Faculty Bibliography

There has been a shift in the study of childhood adversity towards a focus on dimensions of adversity as opposed to a focus on cumulative risk or specific adversities. The Dimensional Model of Adversity and Psychopathology (DMAP) proposes deprivation and threat as core dimensions of childhood adversity. Previous work using DMAP has found links between deprivation and cognitive development and threat and emotional development in adolescence, but few studies have applied this framework to a poverty context, in which children are at heightened risk for adversity experiences, and none have examined outcomes in early childhood. We use data from the Family Life Project (n = 1292) to examine deprivation and threat at child age 24 months as developmental mediators in the association between socioeconomic status (SES) measured at 15 months and executive functions (EF) measured at 48 months. In a multiple mediation model, lower SES was related to higher deprivation and threat. Deprivation was negatively associated with EF, and threat was not associated with EF. Deprivation fully mediated association between SES and EF. These results expand previous work using the DMAP and point to new directions in understanding children's cognitive adaptations to adversity.

Traditionally, executive function (EF) tasks have been scored using either accuracy or reaction time (RT) metrics. The current study, which includes 1,015 first-grade children from the Family Life Project, demonstrates a new scoring approach for the Hearts and Flowers (HF) task that uses both item-level accuracy and RT data to estimate latent EF ability. Our primary aim was to compare scores derived from this approach to standard scores often reported in the HF literature. A second aim was to test whether item-level accuracy and RT data were differentially related to latent EF ability, depending on children's overall level of task performance. Our results indicated that item-level accuracy and RT data both convey unique information related to latent EF ability but that the relative contributions of each source of data vary across children. Accuracy was comparatively more informative of latent ability in children with lower HF task performance, while RT was comparatively more informative of latent ability in children with higher overall performance. Moreover, item-level RT was differentially related to latent EF ability for children in lower versus higher performing groups. Whereas faster responding was associated with higher ability in the higher performing group, slower responding was associated with higher ability for the lower performing group. Latent EF ability was related to criterion measures in ways comparable to traditional scores. Results are discussed in relation to the broader EF assessment literature. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Despite widespread interest in the construct of executive functioning (EF), we currently lack definitive evidence regarding the best measurement model for representing the construct in substantive analyses. The most common practice is to represent EF ability as a reflective latent variable, with child performance on individual EF tasks as observed indicators. The current article critically evaluates the dominant use of reflective latent variable models in the child EF literature and compares them to composite models, a reasonable alternative. We review the literature suggesting that reflective latent variable models may not be the most appropriate representation of the construct of EF. Using preschool (M_age = 48.3 months) and first grade (M_age = 83.5 months) data from the Family Life Project (N = 920), we also investigate the implications of measurement model specification for the interpretation of study findings. Children in this sample varied in terms of sex (49% male), race (43% black) and socioeconomic status (76% low-income). Our findings show that the conclusions we draw from 2 substantive analyses differ depending on whether EF is modeled as a reflective latent variable versus a composite variable. We describe the implications of these findings for research on child EF and offer practical recommendations for producers and consumers of developmental research. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Environmental adversity increases child susceptibility to disrupted developmental outcomes, but the mechanisms by which adversity can shape development remain unclear. A translational cross-species approach was used to examine stress-mediated pathways by which poverty-related adversity can influence infant social development. Findings from a longitudinal sample of low-income mother-infant dyads indicated that infant cortisol (CORT) on its own did not mediate relations between early-life scarcity-adversity exposure and later infant behavior in a mother-child interaction task. However, maternal CORT through infant CORT served as a mediating pathway, even when controlling for parenting behavior. Findings using a rodent "scarcity-adversity" model indicated that pharmacologically blocking pup corticosterone (CORT, rodent equivalent to cortisol) in the presence of a stressed mother causally prevented social transmission of scarcity-adversity effects on pup social behavior. Furthermore, pharmacologically increasing pup CORT without the mother present was not sufficient to disrupt pup social behavior. Integration of our cross-species results suggests that elevated infant CORT may be necessary, but without elevated caregiver CORT, may not be sufficient in mediating the effects of environmental adversity on development. These findings underscore the importance of considering infant stress physiology in relation to the broader social context, including caregiver stress physiology, in research and interventional efforts.

BACKGROUND:Extensive literature in human and animal models has documented an association between maternal smoking during pregnancy and externalizing behavior in offspring. It remains unclear; however, the extent to which postnatal environmental smoke exposure is associated with behavioral development, particularly for children whose mothers did not smoke during pregnancy. The present study examined whether magnitude of exposure to environmental smoke across the first four years of life demonstrated a linear association with later externalizing symptoms. METHODS:Exposure was quantified through salivary cotinine measured when children were 6, 15, 24, and 48 months of age, providing a more accurate quantification of realized exposure than can be estimated from parental report of cigarettes smoked. Data were available for n = 1,096 (50% male; 44% African American) children recruited for the Family Life Project, a study of child development in areas of rural poverty. RESULTS:Analyses indicate a linear association between cotinine and children's symptoms of hyperactivity and conduct problems. This association remained significant after controlling for family poverty level, parental education, parental history of ADHD, hostility, depression, caregiver IQ, and obstetric complications. Furthermore, this association was unchanged when excluding mothers who smoked during pregnancy from the model. CONCLUSIONS:Findings are consistent with animal models demonstrating an effect of environmental exposure to nicotine on ongoing brain development in regions related to hyperactivity and impulsivity, and highlight the importance of mitigating children's exposure to environmental smoke, including sources that extend beyond the parents.

Using data from a large longitudinal sample (N = 1,292) of children and their caregivers in predominantly low-income, nonurban communities, we investigated longitudinal relations between attuned caregiving in infancy, joint attention in toddlerhood, and executive functions in early childhood. The results from path analysis demonstrated that attuned caregiving during infancy predicted more joint attention in toddlerhood, which was in turn associated with better executive function performance in early childhood. Joint attention was a stronger predictor of executive functions for lower-income families. Moreover, joint attention mediated the relation between attuned caregiving and executive functions, and this mediation was amplified for lower-income families. These results highlight joint attention as a key mechanism through which attuned caregiving supports the development of executive functions, particularly for low-income families. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Research on early life adversity has begun a shift from cumulative risk approaches to more dimensional approaches. One such dimensional approach to understanding early life adversity uses dimensions of deprivation and threat to differentially predict developmental outcomes, however this framework has not been applied to the context of poverty-related adversity, which encompasses more than deprivation and threat and is characterized by high levels of both these dimensions. Previous studies have found that experiences of deprivation, but not threat, predict executive functions (EF). We propose a model of deprivation and threat as dimensions of poverty-related adversity, and we hypothesized that deprivation, but not threat, would mediate links between early life socioeconomic status (SES) and EF. Data come from the 15-, 24-, and 48-month visits of the Family Life Project (n=1,292). We used latent variables of deprivation and threat in a multiple mediation model with SES as the main predictor, deprivation and threat as mediators predicting 48 month EF. Lower SES was related to higher levels of both deprivation (beta=-0.597, p < 0.01) and threat (beta=-0.628, p < 0.01). Additionally, deprivation (beta=-0.916, p < 0.01), but not threat (beta= 0.307, p=0.112) was significantly negatively related to EF outcomes. The indirect effect of SES on EF through deprivation was significant (beta= 0.548, p =0.013). Finally, deprivation and threat together fully mediated the relationship between SES and EF. Implications for mental and physical health for children growing up in high-poverty contexts will be discussed

A growing body of research demonstrates that early-life stress exposure is linked to later-life health outcomes, with disparities in outcomes emerging as early as childhood. However, the mechanisms by which early stress might contribute to adverse health effects remain poorly understood. One likely mechanism is via altered glucocorticoid activity. Glucocorticoids (e.g., cortisol in humans) are essential for myriad physiological functions, including the maintenance of cardiovascular tone, provision of anti-inflammatory effects, and regulation of growth, behavior, and cognition. Here we assessed if glucocorticoid levels across infancy and toddlerhood were associated with impaired tissue sensitivity to glucocorticoids (glucocorticoid resistance) in early adolescence. Data come from the Family Life Project, a longitudinal study of 1,292 children and their caregivers living in predominantly low-income non-urban communities. Children's resting levels of cortisol were assayed via saliva samples collected in their home at 6, 15, 24, and 48 months of age. Glucocorticoid resistance at 11-12 years of age was assessed using a well-established protocol whereby whole blood was diluted in phosphate buffered saline and cultured with and without endotoxin lipopolysaccharide (LPS) at a range of concentrations of hydrocortisone. Glucocorticoid resistance was quantified by the difference in inflammatory cytokine (IL-6) levels in response to LPS alone versus LPS with the highest concentration of hydrocortisone. Structural equation modeling was used to assess direct effects of a latent variable of early childhood cortisol on glucocorticoid resistance in early adolescence. All models adjusted for demographic covariates, including infant's race, gender, age, and mother's age, as well as child's body mass index, health status, time of blood draw, and body temperature. Analyses revealed a significant positive association between cortisol levels and glucocorticoid resistance, such that higher cortisol in early childhood predicted increased glucocorticoid resistance in early adolescence (b=0.893, p=0.023). Our findings support the idea that prolonged elevation of glucocorticoids in early life may result in a dysregulated response such that the expression and/or function of glucocorticoid receptors become downregulated, leading to glucocorticoid resistance

Impairments in both executive function and parent-child interactions are associated with child externalizing behavior, but few studies have tested the uniqueness of these associations in the first years of life. Addressing these gaps, the current study involved an international sample (N = 438; 218 boys) who, at 14 and 24 months, completed an innovative battery of executive function tasks and were filmed at home in dyadic interaction with their mothers, enabling detailed observational ratings of maternal support. In addition, parents rated infant temperament at 4 months and externalizing behavior at 14 and 24 months. Cross-lagged longitudinal analysis showed a unidirectional developmental association between executive function at 14 months and externalizing behavior at 24 months. In addition, infant negative affect moderated the inverse association between maternal support at 14 months and externalizing behavior at 24 months. The benefits of maternal support were only evident for children with low levels of negative affect in infancy. We discuss this finding in relation to theoretical models that highlight child effects (e.g., models of vantage sensitivity).

Identifying skills at entry to school that promote academic success has been a major goal for policy and research. The current study categorized school-entry skills as academic (i.e., math and reading skills), cognitive (i.e., language and executive functioning), and social-emotional (i.e., externalizing and internalizing problems) skills and asked to what extent each predicted school-age skills. Data were drawn from the Family Life Project, a representative birth cohort study of 1292 children living in low-wealth rural communities. Children's academic, cognitive, and social-emotional skills were assessed prior to kindergarten and used to predict longitudinal trajectories in math, reading, language, and social-emotional skills from kindergarten through third grade. Findings indicate that school-entry skills within a given domain were the strongest predictor of the level of school-age skills within that domain, but the magnitude of those associations diminished over time. Higher levels of language and executive function, and lower levels of internalizing problems were the only school-entry skills to predict larger gains in skills during the first four years of elementary school. These results suggest that greater focus on both cognitive and social-emotional skills during early childhood may be warranted.