Temperament Development Research Articles

Early-life temperament: A longitudinal investigation of stability and structure

In this longitudinal study, we investigated the factor structure and stability of early-life temperament in a German sample, using three measures developed within Rothbart’s psychobiological approach. Temperament was measured using the Infant Behavior Questionnaire Revised (IBQ-R) at the ages of 6 and 12 months, the Early Childhood Behavior Questionnaire (ECBQ) at the age of 18 months, and the Child Behavior Questionnaire (CBQ) at the ages of 36 and 48 months. We assessed longitudinal stability on a scale and factor level using data from the 85 participants that took part in each measurement. The latent factor structures were analyzed at each time point using all available data, ranging from 112 to 148 participants. Modest to high degrees of stability for most scales and all three latent factors was found. Stability was highest between measurements employing the same instrument and increased with age, indicating a consolidation of temperament traits over time. Model fit for the proposed factor structure consisting of Surgency, Negative Affect, and Effortful Control/Regulatory Capacity was poor, while exploratory factor analyses revealed similar but not identical structures for each time point. The third factor of Regulatory Capacity was not found at 6 months, but at 12 months and later, as is commonly the case in German samples. These findings further contribute to our understanding of the early development of temperament and its stability from infancy and beyond as well as expand on previous literature regarding its structure in German culture.

Microbial exposure at birth and the development of behavioral temperament during the first three years of childhood.

We investigated cross-sectional and longitudinal associations between neonate microbial exposure and emerging behavioral temperament measures at the ages of 1, 2, and 3 years. Infants and mothers (n = 335) were extracted from the Kuopio Birth Cohort Study. Temperament was assessed using the Infant Behavioral and Early Childhood Behavioral Questionnaires. Microbial samples were collected from oral cavity at birth and the bacterial profiles were assessed using 16S rRNA gene sequencing. Microbial diversity was characterized using alpha and beta diversity metrics. Analyses were performed for the most abundant genera. The sample was analyzed as a whole, as well as divided into subgroups representing no antibiotic use during birth (n = 198) and those with antibiotic use during birth (n = 137). No significant associations were observed between microbial profiles and behavioral measures after Bonferroni corrections. Nevertheless, our pre-correction results indicated an association between increased behavioral temperament surgency in the first year and beta diversity (high abundance of Bacteroides, Faecalibacterium and Blautia, low abundance of Lactobacillus) in the antibiotic use group. Additionally, pre-corrections, a high relative abundance of Staphylococcus was associated with increased surgency through years 1, 2, and 3 in the no antibiotics group, prompting consideration into a possible link between antibiotic use and emerging behavioral temperament.

The structure, development, and etiology of observed temperament during middle childhood.

Investigating the structure and etiology of temperament is key to understanding how children interact with the world (Kagan, 1994). Although these topics have yielded an abundance of research, fewer studies have employed observational data during middle childhood, when unique environmental challenges could influence temperament development. To address this gap, Israeli twin children were observed at Age 6.5 (N = 1,083, 564 families; 50.6% females) and again at Age 8-9 (N = 768, 388 families; 52.0% females; 611 children from 322 families had data from both ages). Temperament was assessed globally by trained coders and, at Age 8-9, also by the experimenter who interacted with the child. We examined whether Rothbart et al.'s (2000) three-factor model, according to which temperament includes the domains negative affect, positive affect/surgency, and effortful control, emerges from the data. In addition, we considered a bifactor model, where a fourth global factor accounts for all behaviors' commonality. Across the two ages and rating methods, confirmatory factor analyses supported the bifactor model. The global factor's loadings suggested that it reflects children's expressiveness. Adding this factor changed the associations between the other factors and enabled differentiation between surgency and positive affect. This suggests that in observational settings that capture temperament impressions holistically, children's expressiveness affects other traits' behavioral displays. Twin models revealed genetic influences for most traits. Importantly, twin models revealed shared-environmental influences for negative affect and expressiveness, which modestly contributed to temperament consistency across ages. These findings shed light on temperament traits' interrelatedness and stress the importance of the shared environment to temperament development during middle childhood. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Leveraging machine learning to study how temperament scores predict pre-term birth status

BackgroundPreterm birth (birth at <37 completed weeks gestation) is a significant public heatlh concern worldwide. Important health, and developmental consequences of preterm birth include altered temperament development, with greater dysregulation and distress proneness. AimsThe present study leveraged advanced quantitative techniques, namely machine learning approaches, to discern the contribution of narrowly defined and broadband temperament dimensions to birth status classification (full-term vs. preterm). Along with contributing to the literature addressing temperament of infants born preterm, the present study serves as a methodological demonstration of these innovative statistical techniques. Study designThis study represents a metanalysis conducted with multiple samples (N = 19) including preterm (n = 201) children and (n = 402) born at term, with data combined across investigations to perform classification analyses. SubjectsParticipants included infants born preterm and term-born comparison children, either matched on chronological age or age adjusted for prematurity. Outcome measuresInfant Behavior Questionnaire-Revised Very Short Form (IBQ-R VSF) was completed by mothers, with factor and item-level data considered herein. Results and conclusionsAccuracy estimates were generally similar regardless of the comparison groups. Results indicated a slightly higher accuracy and efficiency for IBQR-VSF item-based models vs. factor-level models. Divergent patterns of feature importance (i.e., the extent to which a factor/item contributed to classification) were observed for the two comparison groups (chronological age vs. adjusted age) using factor-level scores; however, itemized models indicated that the two most critical items were associated with effortful control and negative emotionality regardless of comparison group.

Prenatal Gut Microbiota Predicts Temperament in Offspring at 1-2 Years.

The purpose of this study was to explore whether prenatal gut microbiota (GM) and its functions predict the development of offspring temperament. A total of 53 mothers with a 1-year-old child and 41 mothers with a 2-year-old child were included in this study using a mother-infant cohort from central China. Maternal fecal samples collected during the third trimester were analyzed using 16S rRNA V3-V4 gene sequences. Temperament of the child was measured by self-reported data according to the primary caregiver. The effects of GM in mothers on offspring's temperament were evaluated using multiple linear regression models. The results demonstrated that the alpha diversity index Simpson of prenatal GM was positively associated with the activity level of offspring at 1year (adj. P = .036). Bifidobacterium was positively associated with high-intensity pleasure characteristics of offspring at 1year (adj. P = .031). Comparatively, the presence of Bifidobacterium found in the prenatal microbiome was associated with low-intensity pleasure characteristics in offspring at 2years (adj. P = .031). There were many significant associations noted among the functional pathways of prenatal GM and temperament of offspring at 2years. Our findings support the maternal-fetal GM axis in the setting of fetal-placental development with subsequent postnatal neurocognitive developmental outcomes, and suggest that early childhood temperament is in part associated with specific GM in the prenatal setting.

The roles of parent temperament and parenting styles in adolescent temperament development

This study examined temperament development from early to middle adolescence and the roles of parenting styles and parent temperament in this development. The sample consisted of 842 adolescents (n = 842 in Grade 6; 54% girls) and their parents (N = 707). Adolescents assessed their temperament in Grades 6 and 9 and parents assessed their temperament and parenting styles when adolescents were in Grade 6. The results showed that adolescent affiliativeness increased and effortful control decreased from early to middle adolescence. High parental warmth was related to higher adolescent affiliativeness and higher effortful control, but also to a decrease in adolescent negative affectivity. High parental behavioral control, in turn, was related to adolescents’ initially higher, but subsequently decreasing surgency. Further, high parental psychological control was related to lower adolescent effortful control. Parent temperament was also related to adolescent temperament, and parenting styles partially mediated several associations between parents’ and adolescents’ temperament. The results suggest that parents’ temperament and parenting styles are related to adolescents’ temperament development in a complex manner, even as adolescents seek to gain independence from parents. Understanding the roles of parental temperament and parenting in adolescent temperament development is important in order to support adolescents in their development towards a stable adulthood.

Associations between mothers' and fathers' depression and anxiety prior to birth and infant temperament trajectories over the first year of life: Evidence from diagnoses and symptom severity

BackgroundDevelopmental shifts in infant temperament predict distal outcomes including emerging symptoms of psychopathology in childhood. Thus, it is critical to gain insight into factors that shape these developmental shifts. Although parental depression and anxiety represent strong predictors of infant temperament in cross-sectional research, few studies have examined how these factors influence temperament trajectories across infancy. MethodsWe used latent growth curve modeling to examine whether mothers' and fathers' anxiety and depression, measured in two ways – as diagnostic status and symptom severity – serve as unique predictors of developmental shifts in infant temperament from 3 to 12 months. Participants included mothers (N = 234) and a subset of fathers (N = 142). Prior to or during pregnancy, both parents were assessed for lifetime diagnoses of depression and anxiety as well as current severity levels. Mothers rated their infants' temperament at 3, 6, and 12 months of age. ResultsMothers' depression and anxiety primarily predicted initial levels of temperament at 3 months. Controlling for mothers' symptoms, fathers' depression and anxiety largely related to temperament trajectories across infancy. Lifetime diagnoses and symptom severities were associated with distinct patterns. LimitationsInfant temperament was assessed using a parent-report measure. Including an observational measure would provide a more comprehensive picture of the infants' functioning. ConclusionsThese results indicate that mothers' and fathers' mental health are uniquely associated with infant temperament development when measured using diagnostic status and/or symptom severity. Future studies should examine whether these temperament trajectories mediate intergenerational transmission of risk for depression and anxiety.

Mothers' symptoms of anxiety and depression and the development of child temperament: A genetically informative, longitudinal investigation.

Child temperament traits and mothers' emotional symptoms relating to anxiety and depression may drive changes in one another, leading to their 'co-development' across time. Alternatively, links between mother and child traits may be attributable to shared genetic propensities. We explored longitudinal associations between mothers' emotional symptoms and child temperament traits and adjusted for genetic effects shared across generations. This study is based on the Norwegian Mother, Father and Child Cohort Study (MoBa). Mothers (n=34,060) reported on their symptoms of anxiety and depression, and temperament among offspring (n=42,526), at child ages 1.5, 3 and 5years. Structural equation models parameterised developmental change in traits, and an extended family design adjusted for genetic effects. We found individual differences in stable trait scores and rate of change for all study variables. Longitudinal stability in mothers' emotional symptoms was associated with longitudinal stability in offspring emotionality (r=0.143), shyness (r=0.031), and sociability (r=-0.015). Longitudinal change in mothers' symptoms showed very small or negligible correlations with longitudinal change in child temperament. Both genetic and environmental influences explained the stable longitudinal association between mothers' symptoms and child emotionality. The studied associations between mother and child traits across time appeared to be due to stable, trait-like factors, involving genetic and environmental influence, rather than their co-development. Findings contribute knowledge on how emotional symptoms develop in families across time, and the methods with which we can explore such development.

Juvenile social play predicts docility in Belding’s ground squirrels

We evaluated the hypothesis that social play behavior influences the development of temperament in young animals, using docility as a measure of temperament. We observed the play behavior of juvenile Belding’s ground squirrels (Urocitellus beldingi) during the developmental period in which play primarily occurs and conducted behavioral tests measuring docility at the beginning and toward the end of the play interval. Tests involved handling squirrels and recording their responses. We observed a significant but weak association between body mass and docility at the beginning of the play period, suggesting that docility may vary with size or energetic variables. Docility decreased significantly among juveniles over the play interval, and rates of social play were reliable predictors of change in docility. Juveniles who played at higher rates tended to have greater decreases in docility over the play interval, suggesting that social play might refine temperament toward more active responses in U. beldingi. Rates of social play among juveniles were reliable predictors of their scores on docility tests as yearlings, suggesting that possible effects of juvenile play on docility may extend beyond the juvenile period. Among mothers of juveniles in the study, docility during gestation and lactation were reliable predictors of docility after emergence of young from the natal burrow. However, docility of mothers decreased significantly between gestation and emergence of young, suggesting that although squirrels have individual tendencies toward docility, the expression of these tendencies may be influenced by behavioral context.Significance statementThis study helps to elucidate ways in which juvenile social play influences the development of young animals. Various studies have suggested that juvenile play influences motor, social, and cognitive development. Here, we show an association between juvenile social play and development of temperament in Belding’s ground squirrels (Urocitellus beldingi). Juveniles who engaged in play at higher rates across the play interval had greater behavioral shifts from passive toward active responses. Refinements in temperament toward more proactive behavior might have benefits for young animals such as better preparing them to explore, investigate, and gather information about their social and physical environments as they venture away from their natal areas.

Changes in the gut microbiome in the first two years of life predicted the temperament in toddlers

BackgroundTemperament has been shown to be associated with the change of gut microbiome. There were no longitudinal studies to explore the role of gut microbiome changes in the development of temperament in toddlers. MethodsThis study used longitudinal cohort to investigate the associations between changes in gut microbiome and temperament in toddlers in the first two years of life. Linear regression analysis and microbiome multivariate association with linear models were used to investigate the associations between the gut microbiome and toddlers' temperament. ResultsIn total, 41 toddlers were analyzed. This study found both Shannon and Chao-1 indices at birth were negatively correlated with the sadness dimension; the higher the Shannon and Chao-1 indices at 6 months, the lower the surgency/extraversion dimension scores; the higher the Shannon and Chao-1 indices at 2 years of ages, the lower the cuddliness dimension scores. After adjusting for covariates, beta diversity at birth was strongly associated with the negative affectivity dimension; beta diversity at 1 year of age was strongly associated with the activity level dimension; and beta diversity at 2 years of age was strongly associated with the discomfort and soothability dimension. Compared to Bifidobacterium cluster, this study also found Bacteroides cluster was associated with lower negative affectivity and its sub-dimensions frustration and sadness scores in toddlers. LimitationsGeneralizability of the results remains to be determined. ConclusionResults of this study confirmed the associations between changes in the gut microbiome diversity and composition in the first two years of life and toddlers' temperament.

Validation of the Arabic version of the 35-item TEMPS-M in a community sample of adults

BackgroundTo our knowledge, no brief version of the Temperament Evaluation in Memphis Pisa and San Diego (TEMPS-M) is available so far in the Arabic language, which might have resulted in limited research in this field from Arab countries. We aimed through this study to validate the 35-item TEMPS-M into the Arabic language in a sample of non-clinical Lebanese adults.MethodsWe used an online cross-sectional survey targeting non-clinical Lebanese adults from the general population. A confirmatory factor analysis was conducted to test the factorial structure of the TEMPS-M.ResultsAll five temperament subscales achieved good/very good internal consistencies in the present study (depressive: α = 0.78, cyclothymic: α = 0.86, hyperthymic: α = 0.83, irritable: α = 0.87, and anxious: α = 0.87). The five-factor solution of the TEMPS-M displayed a good CFI of 0.94, TLI of .94 and a GFI of .95, but a poor RMSEA of .10 [90% CI .10, .11]. The five affective temperaments showed positive correlations with personality dysfunction domains, thus attesting for convergent validity. In addition, positive correlations between all affective temperament dimensions and anxiety/depression scores were found. We also tested for gender invariance, and found that configural, metric, and scalar invariance were supported across gender.ConclusionOur data suggest that the psychometric properties of the Arabic TEMPS-M are good. Making this scale available in Arabic will hopefully encourage Arab researchers to investigate this under-explored topic in their countries, and advance knowledge on how culture impacts the prevalence, development and course of temperament.

The Effects of Chinese Parenting Belief on Preschoolers' Temperament and Secure Attachment.

In the past, there were a few studies investigating the effects of parenting belief on preschoolers' temperament and secure attachment. There were some inconsistencies; some effects were also unclear. A total of 2164 parents of three-year-old preschoolers were selected for a panel study named National Longitudinal Study of Child Development and Care. At first, confirmatory factor analysis was conducted to examine construct validity of Chinese parenting belief, preschoolers' temperament, and secure attachment. Consecutively, the effects of Chinese parenting belief on preschoolers' temperament and secure attachment were investigated through structural equation modeling. Results showed: (1) construct validity of Chinese parenting belief (composed of Guan, Jiao, achievement, and Chi beliefs), preschoolers' temperament (composed of extraversion, effortful control, and negative affection temperament) and secure attachment were good. (2) The Guan belief showed no effects on all temperaments and secure attachment. (3) Only Jiao belief contributed to the development of extraversion, effortful control, negative affection, and secure attachment. (4) The Achievement belief had a detrimental effect on the development of secure attachment, but it had no effects on others. (5) The Chi belief can increase the development of negative affection temperament, but it had no effects on the rest.

Trajectories of temperament from late childhood through adolescence and associations with anxiety and depression in young adulthood

Anxiety and depression are pervasive and pernicious mental health problems for young adults. Developmental trajectories of adolescent temperament (Effortful Control, Negative Emotionality, and Positive Emotionality) may help us predict who will experience anxiety/depression during young adulthood. The present study used longitudinal data from a large, community sample of Mexican-origin youth ( N = 674) to examine how temperament develops across adolescence (age 10–16) and whether the developmental trajectories of temperament are associated with anxiety/depression during young adulthood (ages 19 and 21). Results indicate that Effortful Control, Negatively Emotionality, and the Affiliation facet of Positive Emotionality tend to decrease across adolescence, whereas Surgency tends to increase. Smaller decreases in Effortful Control and greater increases in Positive Emotionality across adolescence were associated with fewer anxiety/depression symptoms during young adulthood, whereas smaller decreases in Negative Emotionality were associated with more anxiety/depression symptoms later on. Thus, temperament development serves as both a protective factor (Effortful Control, Positive Emotionality) and a risk factor (Negative Emotionality) for later anxiety/depression in Mexican-origin youth.

Infant temperamental fear, pupil dilation, and gaze aversion from smiling strangers.

In childhood, higher levels of temperamental fear-an early-emerging proclivity to distress in the face of novelty-are associated with lower social responsivity and greater social anxiety. While the early emergence of temperamental fear in infancy is poorly understood, it is theorized to be driven by individual differences in reactivity and self-regulation to novel stimuli. The current study used eye tracking to capture infants' (N=124) reactions to a video of a smiling stranger-a common social encounter-including infant gaze aversions from the stranger's face (indexing arousal regulation) and pupil dilation (indexing physiological reactivity), longitudinally at 2, 4, 6, and 8 months of age. Multilevel mixed-effects models indicated that more fearful infants took more time to look away from a smiling stranger's face than less fearful infants, suggesting that high-fear infants may have slower arousal regulation. At 2 and 4 months, more fearful infants also exhibited greater and faster pupil dilation before gaze aversions, consistent with greater physiological reactivity. Together, these findings suggest that individual differences in infants' gaze aversions and pupil dilation can index the development of fearful temperament in early infancy, facilitating the identification of, and interventions for, risk factors to social disruptions.

Joint analyses of human milk fatty acids, phospholipids, and choline in association with cognition and temperament traits during the first 6 months of life.

Early dietary exposure via human milk nutrients offers a window of opportunity to support cognitive and temperament development. While several studies have focused on associations of few pre-selected human milk nutrients with cognition and temperament, it is highly plausible that human milk nutrients synergistically and jointly support cognitive and behavioral development in early life. We aimed to discern the combined associations of three major classes of human milk nutrients with cognition and temperament during the first 6 months of life when human milk is the primary source of an infant’s nutrition and explore whether there were persistent effects up to 18 months old. The Mullen Scales of Early Learning and Infant Behavior Questionnaires—Revised were used to assess cognition and temperament, respectively, of 54 exclusively/predominantly breastfed infants in the first 6 months of life, whose follow-ups were conducted at 6–9, 9–12, and 12–18 months old. Human milk samples were obtained from the mothers of the participants at less than 6 months of age and analyzed for fatty acids [total monounsaturated fatty acids, polyunsaturated fatty acid, total saturated fatty acid (TSFA), arachidonic acid (ARA), docosahexaenoic acid (DHA), ARA/DHA, omega-6/omega-3 polyunsaturated fatty acids ratio (n-6/n-3)], phospholipids [phosphatidylcholine, phosphatidylethanolamine (PE), phosphatidylinositol (PI), sphingomyelin], and choline [free choline, phosphocholine (PCho), glycerophosphocholine]. Feature selection was performed to select nutrients associated with cognition and temperament. The combined effects of selected nutrients were analyzed using multiple regression. A positive association between the arachidonic acid (ARA) and surgency was observed (p = 0.024). A significant effect of DHA, n-6/n-3, PE, and TSFA concentrations on receptive language (R2 = 0.39, p = 0.025) and the elevated ARA, PCho, and PI with increased surgency (R2 = 0.43, p = 0.003) was identified, suggesting that DHA and ARA may have distinct roles for temperament and language functions. Furthermore, the exploratory association analyses suggest that the effects of human milk nutrients on R.L. and surgency may persist beyond the first 6 months of life, particularly surgency at 12–18 months (p = 0.002). Our study highlighted that various human milk nutrients work together to support the development of cognition and temperament traits during early infancy.

Genetic and environmental influences on temperament development across the preschool period.

Preschoolers' temperament characteristics are associated with children's long-term development. Such links underscore the importance of understanding factors that shape temperament during preschool. This is the first study to examine genetic and environmental sources of developmental growth in three temperament dimensions: surgency, negative affectivity, and effortful control, during the preschool period. Biometric latent growth curve modeling was used to examine genetic, shared, and nonshared environmental contributions to the invariant level of and developmental growth in temperament, using a sample of 310 same-sex twin pairs (MZ = 123, DZ = 187) assessed at 3, 4, and 5 years of age. Temperament was assessed using primary caregiver's report on the Child Behavior Questionnaire-Short Form. All three temperament dimensions demonstrated linear increases from ages 3 to 5 years. The invariant levels of all three temperament dimensions were explained by genetic and nonshared environmental factors. Growth in surgency was fully explained by nonshared environmental factors, while growth in negative affectivity was mainly explained by genetic factors. Growth in effortful control was explained by genetic and nonshared environmental factors, although neither were significant due to large bootstrap standard errors. For negative affectivity and effortful control, the genetic factors that contributed to developmental growth were independent from those associated with their invariant levels. Collectively, these findings indicate that both genetic and nonshared environmental factors play important roles in the invariant levels of temperament. Findings also accord a critical role of children's nonshared environment in the development of surgency and to a lesser extent negative affectivity and effortful control. It is also notable that novel genetic effects contribute to developmental growth in negative affectivity and effortful control as children age, emphasizing the importance of integrating developmental models in genetic research.

Maternal depressive symptoms and early childhood temperament before and during the COVID-19 pandemic in the United Kingdom.

The COVID‐19 pandemic is an unexpected and major global event, with the potential to have many and varied impacts on child development. However, the implications of the pandemic for maternal depressive symptoms, early childhood temperament dimensions, and their associations, remain largely unknown. To investigate this, questionnaires were completed by mothers (N = 175) before and during the pandemic when their child was 10‐ and 16‐months old (Study 1), and by an extended group of mothers with young children (6–48 months; 66 additional mothers) during the first and second national lockdowns in the United Kingdom in 2020 (Study 2). Results indicated that while maternal pandemic‐related stress decreased over the first 6 months of the pandemic, there was an increase in mothers who reported feeling some level of pandemic‐specific depression. Despite this, we did not observe an increase in the severity of global maternal depressive symptoms, or any negative impact of the pandemic on the development of temperament in infancy and early childhood.

Infant colic, young children\u2019s temperament and sleep in a population based longitudinal cohort study

BackgroundColic and sleep problems are common among infants, constitute challenges and distress for parents, and are often reasons for seeking help from health professionals. The literature debates whether infant colic and sleep problems are linked together or not. Further, limited evidence exists on how colic impacts on child temperament and sleep during early childhood. Thus, the purpose of this study was to increase our knowledge of the characteristics of infants with a history of colic compared to infants without, and to study how infant colic is associated with the development of child temperament and sleep over time.MethodsThe study is based on The Norwegian Mother, Father and Child Cohort Study (MoBa), a population-based cohort study conducted by the Norwegian Institute of Public Health. This sample contains 88,186 mothers and children. Data was retrieved from questionnaires distributed to mothers at recruitment (in pregnancy) and when the child was 6 months, 18 months, 3 years, and 5 years. Data was analysed using linear mixed models and GLM models for repeated measures.ResultsAt 6 months, infants with reported colic are described as fussier, present more sleeping problems, are breastfed less, and the families visit the child health centre more often when compared to the non-colic group. Mothers of children with reported colic perceive their children’s temperament significantly more challenging from the age of 6 months to 5 years. Further, children with reported colic were more likely to sleep less than recommended (22%) and to have more frequent night awakenings (14%) than usual for their age (6 months to 5 years).ConclusionInfant colic often occurs together with other signs of regulatory problems which may amplify the load on the parents. Moderate differences in temperament and sleep-problems across time, between those with colic and those without, indicate that the diagnosis of colic is moderately associated with later behavioural difficulties. However, it is demanding for the parents, and important to be aware of and act upon symptoms of colic in the child health centres to reduce the parents’ load and prevent adverse long-term outcomes.

Examination of Early Childhood Temperament of Shyness and Social Avoidance and Associations With Cardiometabolic Health in Young Adulthood

A child temperament characterized by shyness and avoidance of social interactions is associated with poor peer relationships and emotional problems, yet its long-term associations with adult cardiometabolic health are largely unknown. To examine whether a childhood temperament characterized by shyness and avoidance of social interactions is associated with poor cardiometabolic health. This cohort study included participants who were recruited at birth between April 1991 to December 1992 as part of a prospective longitudinal cohort, the Avon Longitudinal Study of Parents and Children. Follow-up assessments of health behaviors and cardiometabolic health extended into young adulthood (age 24 years). Data analysis was conducted between April and October 2021. Parent reports of temperament across ages 3 to 6 years were used to derive childhood temperament profiles in a longitudinal clustering analysis. Accelerometry measures of adolescent moderate to vigorous physical activity (MVPA) from ages 11 to 15 years and adult social occupation class were examined as mediators using path analyses. At age 24 years, 9 cardiometabolic outcomes were measured through anthropometrics and fasting blood samples: triglyceride levels, high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol levels, glycated hemoglobin levels, insulin levels, systolic and diastolic blood pressure, body mass index, and C-reactive protein (CRP) levels. Of the 9491 participants included in the analyses, 4908 (51.7%) were male, and 8668 of 9027 (96.0%) were White. Four childhood temperament profiles were identified: (1) introverted (2810 [29.6%]), (2) extraverted (2527 [26.6%]), (3) conflicted-shy (2335 [24.6%]), and (4) avoidant-shy (1819 [19.2%]). Lower childhood socioeconomic status was a precursor associated with the development of an avoidant-shy temperament (eg, introvert vs avoidant-shy: odds ratio, 1.13; 95% CI, 1.04-1.23). Path analyses showed that avoidant-shy children spent less time in MVPA in adolescence compared with all other temperament profiles (eg, introvert vs avoidant-shy: β = 0.10; b = 0.25; 95% CI, 0.14-0.35; P < .001), which in turn was associated with a cluster of cardiometabolic indices at age 24 years, including lower HDL cholesterol levels (β = 0.07; b = 0.95; 95% CI, 0.12-1.78; P = .03) and higher LDL cholesterol levels (β = -0.07; b = -1.69; 95% CI = -3.32 to -0.06; P = .04), insulin levels (β = -0.10; b = -0.57; 95% CI, -1.04 to -0.10; P = .02), diastolic blood pressure (β = -0.09; b = -0.59; 95% CI, -0.97 to -0.21; P = .002), and body mass index (β = -0.07; b = -0.32; 95% CI, -0.56 to -0.07; P = .01). Additionally, children classified as avoidant-shy attained lower social occupation classes at age 24 years, which was concurrently associated with higher BMI (β = 0.06; b = 0.21; 95% CI, 0.08-0.35; P = .002). Notably, these results were adjusted for a range of early developmental precursors and confounders, suggesting an independent association of temperament. In this cohort study, less engagement in physical activity across adolescence seemed to be a developmental mechanism connecting an avoidant-shy childhood temperament and greater cardiometabolic risks over the life course. Future studies should examine the efficacy of physical activity and social skill programs that specially target the needs of different children to thereby reduce cardiometabolic risks.

Infant sleep and negative reactivity: The role of maternal adversity and perinatal sleep

Sleep during infancy contributes to the development and maintenance of infant regulatory functioning and may be an early risk marker for more difficult temperamental traits like negative reactivity. Further, maternal adverse childhood experiences (ACEs) may predispose individuals to greater sleep disturbances in adulthood and have been linked with sleep disturbances in both mothers and infants. Thus, examining maternal history of ACEs and maternal sleep difficulties during pregnancy and postpartum may provide insight into underlying risk factors affecting infant sleep difficulties and early temperament development. Fifty-nine mothers from a diverse, community sample (44% white) completed questionnaires on ACEs, maternal sleep, infant sleep, and infant temperament at 30-weeks gestation, 6-weeks postpartum, and 16-weeks postpartum. Results indicated that maternal ACES and sleep problems during pregnancy have long term implications for infant negative reactivity at 16-weeks, with significant indirect effects through maternal and infant sleep problems at 6-weeks. Addressing psychosocial functioning and prenatal sleep during pregnancy, particularly among women with high ACEs, may be a target of intervention to improve maternal and infant sleep health during the postpartum, and reduce the risk for difficult infant temperament.