The structure and stability of temperament from infancy to toddlerhood: a one-year prospective study

Developmental Trajectories of Irritability across the Transition to Toddlerhood: Associations with Effortful Control and Psychopathology

Preschool-age irritability is a transdiagnostic marker of internalizing and externalizing problems. However, researchers have generally been reluctant to examine irritability within a clinically salient framework at younger ages due to some instability during the "terrible twos" period. Developmentally sensitive and dense measurements to capture intra- and inter-individual variability, as well as exploration of developmental processes that predict change, are needed. This study aimed to examine (1) the trajectories of irritability at the transition to toddlerhood (12-24 months of age) using repeated measures, (2) whether effortful control was associated with individual differences in level and growth rate of irritability, and (3) whether individual differences in the irritability trajectories were associated with later psychopathology. Families were recruited when the child was 12-18 months old (N = 333, 45.65% female). Mothers reported on their toddler's irritability at baseline and every two months until a follow-up laboratory assessment approximately one year later. Effortful control was measured at baseline. Clinical internalizing/externalizing symptoms were measured at the follow-up assessment. Hierarchical linear models revealed an increase in irritability over time, yet there was relatively little within-person variability. Effortful control was only associated with the level of irritability and not growth rate. Level of irritability was associated with internalizing, externalizing, and combined symptoms, but growth rate was not. Findings suggest intraindividual stability in irritability at the transition to toddlerhood and the possibility that screening for elevated irritability at toddler age is meaningful.

Infant gut microbiota and negative and fear reactivity

BACKGROUND

Studies indicate that gut microbiota is related to neurodevelopmental and behavioral outcomes. Accordingly, early gut microbiota composition (GMC) has been linked to child temperament, but research is still scarce. The aim of this study was to examine how early GMC at 2.5 months is associated with child negative and fear reactivity at 8 and 12 months since they are potentially important intermediate phenotypes of later child psychiatric disorders.

METHODS

Our study population was 330 infants enrolled in the longitudinal FinnBrain Birth Cohort Study. Gut microbiota composition was analyzed using stool sample 16s rRNA sequencing. Negative and fear reactivity were assessed using the Laboratory Temperament Assessment Battery (Lab-TAB) at child's age of 8 months (n =150) and the Infant Behavior Questionnaire-Revised Short Form (IBQ-R SF) at child's age of 12 months (n = 276).

CONCLUSIONS

We found a positive association between alpha diversity and reported fear reactivity and differing microbial community composition based on negative reactivity for boys. Isobutyric acid correlated with observed negative reactivity, however, this association attenuated in the linear model. Several genera were associated with the selected infant temperament traits. This study adds to the growing literature on links between infant gut microbiota and temperament informing future mechanistic studies.

The Interplay between Socioeconomic Status, Parenting and Temperament Predicts Inhibitory Control at Two Years of Age

This paper investigates the interplay between environmental factors (socioeconomic status (SES) and parenting) and temperament in the development of inhibitory control (IC) at 2 years of age. We administered to toddlers (n = 59) a delay of gratification task which measures IC in the context of self-regulation. Parents reported their toddlers' temperament, parenting strategies, and SES. We hypothesized that poorer IC would be associated with more reactive temperament, less effortful control, lower SES and inconsistent/coercive parenting practices. Finally, we explored the interaction between temperament, parenting and SES. We found that both coercive parenting and low-SES were negatively correlated to IC at the age of 2 years. Temperamental reactivity was unrelated to IC, whereas temperamental effortful control (EC) was positively associated with IC. Results revealed a moderation effect of EC on the influence of coercive parenting and SES in toddlers' IC. Toddlers from lower SES backgrounds and with lower EC were more affected by inconsistent/coercive parenting practices and showed the poorest IC. In contrast, toddlers exhibiting high and average levels of EC seemed to be protected from the detrimental effect of low-SES and inconsistent/coercive parenting on IC. These results suggest that strengthening toddlers' EC and improving parents' parenting skills might be especially relevant for the development of IC in the context of self-regulation, particularly by preventing self-regulatory problems in children from socioeconomically deprived environments. Future studies with larger samples, focusing on populations from severe socioeconomically deprived environments, or intervention studies will be needed in order to confirm and expand our findings.

Relations between bedtime parenting behaviors and temperament across 14 cultures

Objectives

The present study examined parental sleep-supporting practices during toddlerhood in relation to temperament across 14 cultures. We hypothesized that passive sleep-supporting techniques (e.g., talking, cuddling), but not active techniques (e.g., walking, doing an activity together), would be associated with less challenging temperament profiles: higher Surgency (SUR) and Effortful Control (EC) and lower Negative Emotionality (NE), with fine-grained dimensions exhibiting relationships consistent with their overarching factors (e.g., parallel passive sleep-supporting approach effects for dimensions of NE).

Methods

Caregivers (N = 841) across 14 cultures (M = 61 families per site) reported toddler (between 17 and 40 months of age; 52% male) temperament and sleep-supporting activities. Utilizing linear multilevel regression models and group-mean centering procedures, we assessed the role of between- and within-cultural variance in sleep-supporting practices in relation to temperament.

Results

Both within-and between-culture differences in passive sleep-supporting techniques were associated with temperament attributes, (e.g., lower NE at the between-culture level; higher within-culture EC). For active techniques only within-culture effects were significant (e.g., demonstrating a positive association with NE). Adding sleep-supporting behaviors to the regression models accounted for significantly more between-culture temperament variance than child age and gender alone.

Conclusion

Hypotheses were largely supported. Findings suggest parental sleep practices could be potential targets for interventions to mitigate risk posed by challenging temperament profiles (e.g., reducing active techniques that are associated with greater distress proneness and NE).

Effects of Maternal and Child Lifetime Traumatic Stress Exposures, Infant Temperament, and Caregiving Quality on Preschoolers' Executive Functioning

We examined effects of maternal and child lifetime traumatic stress exposures, infant temperament, and caregiving quality on parent ratings of preschoolers' executive functioning (EF). Maternal lifetime trauma was associated with preschoolers' EF problems; this association was mediated by greater child trauma exposure. Infant temperament was associated with EF abilities, particularly among females. Among males, infant extraversion/surgency mediated the association of maternal lifetime trauma with poorer child EF. Caregiving quality was negatively associated with maternal and child trauma exposures but did not predict child EF. Findings have implications for interventions to identify children at risk for poor EF and optimize outcomes.

Presence at a distance: Video chat supports intergenerational sensitivity and positive infant affect during COVID-19

COVID-19 disrupted infant contact with people beyond the immediate family. Because grandparents faced higher COVID-19 risks due to age, many used video chat instead of interacting with their infant grandchildren in person. We conducted a semi-naturalistic, longitudinal study with 48 families, each of whom submitted a series of video chats and surveys, and most (n = 40) also submitted a video of an in-person interaction. Families were mostly highly-educated, White/Caucasian, and lived between 1 and 2700 miles apart. We used multilevel models to examine grandparents' and parents' sensitivity during video chat across time (centered at February 1, 2021, the approximate date of vaccine availability). Grandparent video chat sensitivity changed as a function of date and parent sensitivity. Parent sensitivity changed as a function of date, grandparent sensitivity, and geographic distance. We then modeled infants' affective valence during video chat and in-person interactions with their grandparents, which was only predicted by grandparent sensitivity, not modality or other factors. This study demonstrates that caregivers were sensitive toward infants during video chat interactions despite fluctuations in family stress and reduced in-person contact during COVID-19 and that grandparent sensitivity predicted positive infant affect during both video chat and in-person interactions.

Growth in emotion understanding across early childhood: A cohort-sequential model of firstborn children across the transition to siblinghood

Emotion understanding develops rapidly in early childhood. Firstborn children (N = 231, 55% girls/45% boys, 86% White, 5% Black, 3% Asian, 4% Latinx, M_age  = 29.92 months) were recruited into a longitudinal study from 2004 to 2008 in the United States and administered a series of tasks assessing eight components of young children's emotion understanding from ages 1 to 5. Cohort sequential analysis across three cohorts (1-, 2-, and 3-year-olds) demonstrated a progression of children's emotion understanding from basic emotion identification to an understanding of false-belief emotions, even after controlling for children's verbal ability. Emotion understanding scores were related to children's theory of mind and parent reports of empathy, but not emotional reactivity, providing evidence of both convergent and discriminant validity.

Factor Structure and Measurement Invariance of the Very Short Form of Infant Behavior Questionnaire-Revised (IBQR-VSF): A Study among Vietnamese Children

The Infant Behavior Questionnaire-Revised (IBQ-R) assesses the temperament of infants in Western and non-Western countries. Although its factor analyses revealed three factors—surgency, negative affectivity, and effortful control—in the Western culture, the degree to which these are universal or culturally specific is unclear. This study developed a Vietnamese version of the IBQ-Revised Very Short Form (R-VSF) and examined its factor structure in a Vietnamese population. The Vietnamese IBQ-R VSF was administered to 292 mothers of infants between the ages of 3 and 18 months in Nha Trang city, Vietnam, between July and September 2019. After deleting items to achieve sufficient Cronbach’s alphas for each scale (surgency, negative affectivity, and orienting/regulation), the remaining 28 items were aggregated to parcels subjected to exploratory factor analyses (EFAs). EFAs revealed a 3-factor model corresponding to the original theory, and confirmatory factor analyses indicated a good fit of this structural model. The final 3-factor model with parcels indicated measurement and structural invariance between mothers of boys and girls.

Stability and structure of infant and toddler temperament in two longitudinal studies in Germany

The present study investigated the factor structure and longitudinal stability of infant and toddler temperament measured with the Infant Behavior Questionnaire-Revised (IBQ-R) and the Early Childhood Behavior Questionnaire (ECBQ) in two German samples. Since the few studies using the German IBQ-R failed to replicate the commonly assumed three factors of infant temperament, another exploration of its factor structure was necessary. Whereas previous stability measurements are usually based on groups with relatively large age ranges, we investigated stability between concrete ages. In Study 1, the IBQ-R was applied in 9- and 12-month-old infants. In Study 2, both questionnaires were applied in 12-, 18-, and 24-month-olds. Factor analyses of the IBQ-R in both studies revealed a two-factor solution comprising Surgency/ Extraversion and Negative Affectivity, replicating earlier findings with German infants. The Orienting/ Regulation factor was not replicated for the IBQ-R, whereas analysis of the ECBQ revealed a three-factor solution for toddlers. The results showed stability of temperament ratings within infancy (Study 1) and toddlerhood (Study 2) as well as between the developmental periods within the second year of life (Study 2). Taken together, the present findings indicate that temperament stability emerges early in life and can be reliably measured using the IBQ-R and ECBQ, whereas the factor structure of temperament in infancy requires further validation.

Development and validation of the Early Executive Functions Questionnaire: A carer-administered measure of Executive Functions suitable for 9- to 30-month-olds

Executive functions (EFs) enable us to control our attention and behavior in order to set and work toward goals. Strong EF skills are linked to better academic performance, and greater health, wealth, and happiness in later life. Research into EF development has been hampered by a lack of scalable measures suitable for infancy through to toddlerhood. The 31-item Early Executive Functions Questionnaire (EEFQ) complements temperament measures by targeting cognitive and regulatory capabilities. Exploratory Factor Analysis (n = 486 8- to 30-month-olds) and Confirmatory Factor Analysis (n = 317 9- to 30-month-olds) indicate Inhibitory Control, Flexibility, and Working Memory items load onto a common "Cognitive Executive Function (CEF)" factor, while Regulation items do not. The CEF factor shows strong factorial measurement invariance for sex, and partial strong factorial measurement invariance for age. CEF and Regulation scores show limited floor and ceiling effects, good internal consistency, short-term stability, and convergent validity with carer-report measures of attentional control. The EEFQ is sensitive to developmental change. Results indicate that the widely overlooked period between late infancy and early toddlerhood may be a sensitive period for EF development. The low-resource demands of the EEFQ afford the possibility to study emergent EFs at scale; opening up new opportunities in basic developmental and intervention research.

Temperament and sleep behaviors in infants and toddlers living in low-income homes

Temperament is a dynamic trait that can be shaped by maturity and environmental experiences. In this study, we sought to determine whether and the extent to which temperament was predicted by sleeping behaviors in an understudied sample of primarily Black and White infants and toddlers living in low-income homes (N = 150). Sleeping behaviors were assessed at 15-19 months of age with caregiver report of the Tayside Children's Sleep Questionnaire. Temperament was examined as effortful control, negativity, and surgency with the Infant Behavior Questionnaire Very Short Form at 9-12 months of age and with the Early Childhood Behavior Questionnaire Short Form at 20-24 months of age. Covariates were maternal education, household income, and child sex and race. Continuous variables were standardized, then missing data from independent variables were multiply imputed in 20 datasets. Regression analyses showed that about 1 SD improvement in toddler sleep behaviors significantly predicted about 1/5 SD better toddler effortful control. However, sleep behaviors did not significantly predict toddler surgency or negative affect. This study shows that for a sample of infants and toddlers in low-income homes, how a child learns to regulate sleeping behaviors may influence the development of overall effortful control about six months later.

Prenatal origins of temperament: Fetal cardiac development & infant surgency, negative affectivity, and regulation/orienting

Temperament, i.e. individual differences in reactivity and self-regulation, emerges early in infancy; might temperament originate during fetal development? Mixed findings and methodological issues in the literature examining this consideration limit our understanding of the continuity between these fetal indices and infant temperament. The primary aims of the current study were to improve on published studies by (a) using standardized and well-accepted fetal cardiac (actocardiograph) and infant temperament measures (the Infant Behavior Questionnaire-Revised; IBQ-R) (b) expanding fetal assessments to include coupling (the cross correlation of heart rate with movement), and (c) examining a diverse sample to determine if findings of associations between fetal neurobehavior and infant temperament generalize beyond cohorts that are demographically well-resourced and predominantly white. Building on theory and empirical findings, we hypothesized that (1) FHR would be positively associated with Surgency and Negative Affectivity, (2) FHRV would be positively associated with Surgency, and Regulation/Orienting and inversely associated with Negative Affectivity, and (3) fetal coupling would be positively associated with Regulation/Orienting and Surgency and inversely associated with Negative Affectivity. We collected 20 min of fetal data (m gestational age = 34.42 weeks) and mothers completed the IBQ-R (n = 90 women; 60 % non-Caucasian race; 63 % Latina ethnicity). We found that FHR was positively associated with Negative Affectivity but not associated with Surgency (or Regulation/Orienting). FHRV was inversely associated with Surgency but not associated with Negative Affectivity or Regulation/Orienting. Coupling was positively associated with Regulation/Orienting and Surgency but not associated with Negative Affectivity. Our findings, from a more diverse sample and with established measures, provide further evidence that individual differences in reactivity and regulation can be identified in the in-utero period and show theory-based continuity to specific infant temperament constructs.

The Infant Behavior Questionnaire - Revised: psychometric properties at 2 weeks, 3, 6 and 12 months of life

BACKGROUND

Temperament characteristics are key elements for infants' development. The Infant Behavior Questionnaire - Revised (IBQ-R) is one of the most used measures to assess temperament in infants aged between 3 and 12 months. Its reliability and factor structure have not yet been examined in infants younger than 3 months.

AIMS

To analyze the reliability of the IBQ-R at 2 weeks and the IBQ-R factor structure from 2 weeks to 12 months of life.

METHOD

A longitudinal repeated measures design was used. Three hundred mothers completed the IBQ-R when their infants were 2 weeks, and 3, 6 and 12 months.

RESULTS

At 2 weeks the proportion of "non-applicable" responses was higher in duration of orienting, high intensity pleasure, approach and smiling and laughter scales. The Cronbach's alpha for the IBQ-R dimensions ranged between 0.62 and 0.63 and the McDonald's omega ranged between 0.67 and 0.80, all dimensions exhibited a mean-scale correlation above 0.15, and more than half of the scales revealed a scale-dimension correlation higher than 0.30. The same factor structure was found at 2 weeks, and at 3, 6, and 12 months: surgency/extraversion, p < 0.001, negative affectivity, p < 0.001, and orienting regulation, p = 0.007.

CONCLUSIONS

The IBQ-R may be applied in the first weeks of life and its factor structure remains stable when applied across different ages throughout infancy.

Parental internalizing disorder and the developmental trajectory of infant self-regulation: The moderating role of positive parental behaviors

Child self-regulation (SR), a key indicator for later optimal developmental outcomes, may be compromised in the presence of parental mental disorders, especially those characterized by affective dysregulation. However, positive parental behaviors have been shown to buffer against such negative effects, especially during infancy when SR shows great plasticity to environmental inputs. The current study investigated the effect of maternal and paternal lifetime and current internalizing disorders on the developmental trajectory of infant SR from 3 to 24 months, and the potential moderating role of positive parental behaviors. A latent growth model revealed that SR increased overall from 3 to 24 months. Mothers' positive parental behaviors demonstrated significant moderation effects, such that maternal lifetime internalizing disorder was associated with higher SR intercept only among those with low levels of positive parental behavior. Mothers' lifetime internalizing disorder was also associated with a lower linear slope in SR development with a moderate effect size. Fathers' current internalizing disorder was significantly associated with a higher intercept and lower linear slope of the SR trajectory. The current study expands the infant SR literature by describing its early developmental trajectory as well as early risk and protective factors within the parent-infant environment, taking into consideration developmental inputs from both parents.

Interaction between maternal and paternal parenting styles with infant temperament in emerging behavior problems

This study examined the interaction effects of infant temperament (negative affect, orienting/regulatory capacity, surgency) on the relationship between maternal and paternal parenting styles (authoritative, authoritarian, permissive) and externalizing and internalizing behaviors simultaneously. A diverse sample of mothers (N = 186) and fathers (N = 142) reported on infant temperament of their 6-month-olds and their children's internalizing and externalizing behaviors one year later. Significant interactions revealed: (a) surgency moderated maternal authoritative and paternal permissive parenting style and externalizing behaviors; and (b) surgency moderated maternal authoritarian and paternal authoritative parenting style and internalizing behaviors. No significant interactions were found between maternal and paternal parenting styles and their report of their infants' orienting/regulatory capacity and negative affect. Findings suggest interaction effects may appear beginning in infancy.

The Interaction Between Child Behavioral Inhibition and Parenting Behaviors: Effects on Internalizing and Externalizing Symptomology

Both child temperament and parenting have been extensively researched as predictors of child outcomes. However, theoretical models suggest that specific combinations of temperament styles and parenting behaviors are better predictors of certain child outcomes such as internalizing and externalizing symptoms than either temperament or parenting alone. The current qualitative review examines the interaction between one childhood temperamental characteristic (child behavioral inhibition) and parenting behaviors, and their subsequent impact on child psychopathology. Specifically, the moderating role of parenting on the relationship between child behavioral inhibition and both internalizing and externalizing psychopathology is examined, and the methodological variations which may contribute to inconsistent findings are explored. Additionally, support for the bidirectional relations between behavioral inhibition and parenting behaviors, as well as for the moderating role of temperament on the relationships between parenting and child outcomes, is briefly discussed. Finally, the clinical applicability of this overall conceptual model, specifically in regard to future research directions and potential clinical interventions, is considered.

Longitudinal interplay of young children's negative affectivity and maternal interaction quality in the context of unequal psychosocial resources

Interaction quality and child temperament predict early and later child development. Research hints at transactional interrelations of both aspects but lacks adequate data to examine this assumption. Maternal psychosocial resources are suspected moderators in this context but rarely taken into account. Drawing on data of the German National Educational Panel Study we conducted a cross-lagged panel analysis on the longitudinal interplay of maternal interaction quality and children's negative affectivity at 6-8, 16-18, and 25-27 months and compared mothers with and without accumulated strains. Both variables showed moderate to high structural and rank order stability over time and low but increasing connections. In the case of accumulated stress factors, interaction quality is clearly impaired and high negative affectivity acts as an additional burden while low negative affectivity helps strained mothers to maintain higher interaction quality but only in the first year of life.

Stability of child temperament: Multiple moderation by child and mother characteristics

This 3-wave longitudinal study focuses on stability of child temperament from 3 to 6 years and considers child age, gender, birth order, and term status as well as mother age, education, anxiety, and depression as moderators of stability. Mothers of approximately 10,000 children participating in the Avon Longitudinal Study of Parents and Children rated child temperament. Stability coefficients for child temperament scales were medium to large, and stability was generally robust across moderators except child gender and birth order and mother age and education, which had small moderating effects on reports of stability of child temperament. Statement of contribution What is already known on this subject? Some is known about the stability of temperament in infancy in small samples, but much less is known about the stability of temperament in early childhood or its moderation. What does this study add? This study uses a large sample (˜10,000) to trace the stability of temperament from 3 to 6 years in three waves and considers child age, gender, birth order, and term status as well as mother age, education, anxiety, and depression as moderators of stability.

Emerging behavior problems: Bidirectional relations between maternal and paternal parenting styles with infant temperament

The present study examined bidirectional effects between maternal and paternal parenting styles (authoritative, authoritarian, permissive) and infant temperament (negative affect, orienting/regulatory capacity, surgency) in a diverse sample of 201 mothers and 151 fathers. Using 3 waves of longitudinal data (prenatal, 6 months, and 18 months), this study examined (a) whether maternal and paternal parenting styles prospectively predicted infant temperament; (b) whether mother- and father-reported infant temperament domains predicted parenting styles at 18 months; and (c) whether infant temperament and parenting styles at 6 months predicted parent-reported externalizing and internalizing problem behaviors at 18 months. Mothers and fathers reported on their expected parenting styles at all three waves, infant temperament at 6 months, and their toddler's emerging internalizing and externalizing problems at 18 months. Prospective parenting style effects revealed that maternal authoritative and permissive parenting style predicted infant orienting/regulatory capacity. Child evocative effects indicated infant orienting/regulatory capacity and negative affect predicted greater maternal permissive parenting style. Significant prospective parenting style effects on infant temperament and child evocative effects on paternal parenting style were largely not observed. Several parenting styles and infant temperament domains at 6 months predicted toddlers' externalizing and internalizing problem behaviors but results differed by parent. Findings suggest maternal prenatal perceptions of parenting style predict infant temperament, but temperament can also affect subsequent parenting. More research is needed to identify fathers' bidirectional effects including how fathering is affected by their children's characteristics. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Temperament and self-esteem in high-risk offspring of bipolar parents: Vulnerability and scar effects

BACKGROUND

The nature of the temporal relationship between psychological factors and mood episodes is unclear. The objectives of this study were to determine if temperament and self-esteem predict the onset of mood episodes, and if prior mood episodes influence the stability of these factors over time in high-risk offspring of bipolar parents.

METHODS

Offspring of a parent with bipolar disorder participating in the Flourish Prospective Offspring Study were clinically assessed repeatedly using semi-structured KSADS-PL/SADS-L format interviews, and completed repeated measures of self-esteem, and temperament. Shared frailty survival models and mixed effects regression models were used to determine if psychological factors predicted incident mood episodes, and whether these factors change over time after the incident mood episode, respectively.

RESULTS

Emotionality, shyness and self-esteem were not associated with the hazard of incident major depression; however, increased activity reduced the hazard of this outcome (hazard ratio [HR]: 0.51; 95% CI: 0.27, 0.98). Emotionality and shyness scores increased, while sociability, activity and self-esteem scores decreased after the incident major depressive episode (emotionality: mean change [MC]: 0.35, p = 0.0289; shyness: MC: 0.40, p = 0.0196; sociability: MC: -0.49, p = 0.0001, activity: MC: -0.32, p = 0.0001; self-esteem: MC: -0.79, p = 0.001).

LIMITATIONS

Psychological measures were based on self-report and some models had low numbers limiting the numbers of covariates included as potential confounders.

DISCUSSION

Among the assessed temperamental dimensions, activity showed a protective effect for major depressive episode onset suggesting this temperamental characteristic could serve as a protective target in high risk youth. Conversely, all assessed psychological factors shifted towards increased vulnerability after the first depressive episode.

The role of sustained attention, maternal sensitivity, and infant temperament in the development of early self-regulation

This study investigated infant predictors of early cognitive and emotional self-regulation from an intrinsic and caregiving environmental perspective. Sustained attention, reactive aspects of infant temperament, and maternal sensitivity were assessed at 10 months (n = 124) and early self-regulation (including executive functions, EF, and emotion regulation) was assessed at 18 months. The results indicated that sustained attention predicted early EF, which provide empirical support for the hierarchical framework of EF development, advocating early attention as a foundation for the development of cognitive self-regulation. Maternal sensitivity and surgency predicted emotion regulation, in that infants of sensitive mothers showed more regulatory behaviours and a longer latency to distress, whereas high levels of surgency predicted low emotion regulation, suggesting both the caregiving environment and temperament as important in the development of self-regulation. Interaction effects suggested high sustained attention to be a protective factor for children of insensitive mothers, in relation to emotion regulation. In addition, high levels of maternal sensitivity seemed to foster development of emotion regulation among children with low to medium levels of sustained attention and/or surgency. In all, our findings point to the importance of both intrinsic and extrinsic factors in infant development of self-regulation.

Mothering and anxiety: Social support and competence as mitigating factors for first-time mothers

This study investigated anxiety as a phenomenon distinct from depression and evaluated several variables that influence anxiety in first-time mothers. This explored the relationship between maternal sense of competence (both of mothering and efficacy) and perceived social support (from family, friends, and significant others) and first-time mothers' postpartum anxiety, when depression, socioeconomic status (SES), and marital status were controlled for. The population studied were 86 first-time mothers made up of women with children 24 months or younger in two populations of Kentucky and Michigan. The constructs of maternal sense of competence and perceived social support were found to be significant in explaining first-time mothers' anxiety. The study concluded that a combined association of perceived social support and maternal sense of competence were associated with a 34% (change in R-squared = .339) decrease of a first-time mothers' anxiety. However, not all types of social support, or maternal competence appeared to be equally important with regards to maternal anxiety: social support from friends and family and maternal sense of competence in regard to productivity appeared to be most significant. Lastly, some recommendations for health practitioners who work with mothers are provided.

The Association Between Infant Temperament and Breastfeeding Duration: A Cross-Sectional Study

BACKGROUND

Little is known about the relationship between infant temperament and breastfeeding. The few studies investigating this report mixed results. Some suggest that difficult infants are breastfed for shorter duration, others report opposing results or no association between the two.

AIM

This study investigated associations between infant difficult temperament and breastfeeding duration in a nationally representative cohort of Irish 9-month-old infants.

METHODS

Breastfed, normal birth-weight singletons from The Infant Cohort of the Growing Up in Ireland Study (n = 5,955) were considered in this research. The Infant Characteristics Questionnaire (ICQ), completed by the mother, was used to assess four different dimensions of difficult temperament: fussy, unpredictable, unadaptable, and dull. Our main interest was the fussy dimension as this is captured best by the ICQ. Initially, a logistic regression (LR) model having the binary version, short (<90 days) or long breastfeeding (≥90 days) as outcome variable, was constructed. Next, a proportional odds logistic regression (POLR) model examining the five-level categorical version (≤1 week, 2 weeks-<1 month, 1-<3 months, 3-<6 months, and ≥6 months) of breastfeeding duration was developed. All regression models were adjusted for relevant sociodemographic data.

RESULTS

A total of 3,119 infants were breastfed for less than 90 days, while 2,836 were breastfed for 90 days or longer. The LR and POLR models showed a mild inverse association between infant fussiness/difficultness and breastfeeding duration (LR: OR = 0.98, 95% CI: 0.97-0.99, POLR: OR = 0.98, 95% CI: 0.97-0.99). Higher infant unpredictability is associated with longer breastfeeding duration (LR: OR = 1.04, 95% CI: 1.02-1.07, POLR: OR = 1.04, 95% CI: 1.02-1.06).

CONCLUSIONS

In this cross-sectional study, we found that breastfeeding duration was inversely associated with infant fussiness and positively associated with infant unpredictability.

Maternal anxiety from pregnancy to 2 years postpartum: transactional patterns of maternal early adversity and child temperament

The aims of this study were to examine the anxiety trajectories of women from pregnancy to 2 years postpartum and to assess the influence of their early life experiences and the temperament of the child on these trajectories. We evaluated state anxiety (State-Trait Anxiety Inventory) at pregnancy and 3, 6, 12, 18, and 24 months postpartum and determined its course as a function of self-reported early adverse experiences (Childhood Trauma Questionnaire) and the temperament of the child at 18 months (Early Child Behavior Questionnaire). Based on growth curve modeling, we found that anxiety followed a general U-shape pattern from gestation to 2 years postpartum, which was modified by early life experience of women. Greater early adversity was associated with higher gestational anxiety, followed by a marked decrease once the baby was born, and subsequent increase during the later postpartum period. The temperament of the child also modulated anxiety trajectories. Thus, mothers of children high in negative affectivity and who also experienced greater early adversity had elevated and flat anxiety trajectories, while child extraversion was associated with increasing anxiety courses approaching 2 years postpartum. These results show that maternal anxiety dynamically changes through the postpartum period with a course that is affected by previous and current experiences.

Infant temperament: stability by age, gender, birth order, term status, and socioeconomic status

Two complementary studies focused on stability of infant temperament across the 1st year and considered infant age, gender, birth order, term status, and socioeconomic status (SES) as moderators. Study 1 consisted of 73 mothers of firstborn term girls and boys queried at 2, 5, and 13 months of age. Study 2 consisted of 335 mothers of infants of different gender, birth order, term status, and SES queried at 6 and 12 months. Consistent positive and negative affectivity factors emerged at all time points across both studies. Infant temperament proved stable and robust across gender, birth order, term status, and SES. Stability coefficients for temperament factors and scales were medium to large for shorter (< 9 months) interassessment intervals and small to medium for longer (> 10 months) intervals.

Gut microbiome composition is associated with temperament during early childhood

BACKGROUND

Understanding the dynamics of the gut-brain axis has clinical implications for physical and mental health conditions, including obesity and anxiety. As such disorders have early life antecedents, it is of value to determine if associations between the gut microbiome and behavior are present in early life in humans.

METHODS

We used next generation pyrosequencing to examine associations between the community structure of the gut microbiome and maternal ratings of child temperament in 77 children at 18-27months of age. It was hypothesized that children would differ in their gut microbial structure, as indicated by measures of alpha and beta diversity, based on their temperamental characteristics.

RESULTS

Among both boys and girls, greater Surgency/Extraversion was associated greater phylogenetic diversity. In addition, among boys only, subscales loading on this composite scale were associated with differences in phylogenetic diversity, the Shannon Diversity index (SDI), beta diversity, and differences in abundances of Dialister, Rikenellaceae, Ruminococcaceae, and Parabacteroides. In girls only, higher Effortful Control was associated with a lower SDI score and differences in both beta diversity and Rikenellaceae were observed in relation to Fear. Some differences in dietary patterns were observed in relation to temperament, but these did not account for the observed differences in the microbiome.

CONCLUSIONS

Differences in gut microbiome composition, including alpha diversity, beta diversity, and abundances of specific bacterial species, were observed in association with temperament in toddlers. This study was cross-sectional and observational and, therefore, does not permit determination of the causal direction of effects. However, if bidirectional brain-gut relationships are present in humans in early life, this may represent an opportunity for intervention relevant to physical as well as mental health disorders.

Parent-reported temperament trajectories among infant siblings of children with autism

Temperament atypicalities have been documented in infancy and early development in children who develop autism spectrum disorders (ASD). The current study investigates whether there are differences in developmental trajectories of temperament between infants and toddlers with and without ASD. Parents of infant siblings of children with autism completed the Carey Temperament Scales about their child at 6, 12, 18, 24, and 36 months of age. Temperament trajectories of children with ASD reflected increases over time in activity level, and decreasing adaptability and approach behaviors relative to high-risk typically developing (TD) children. This study is the first to compare temperament trajectories between high-risk TD infants and infants subsequently diagnosed with ASD in the developmental window when overt symptoms of ASD first emerge.

From positive emotionality to internalizing problems: the role of executive functioning in preschoolers

Temperament and psychopathology are intimately related; however, research on the prospective associations between positive emotionality, defined as a child's positive mood states and high engagement with the environment, and psychopathology is inconclusive. We examined the longitudinal relation between positive emotionality and internalizing problems in young children from the general population. Furthermore, we explored whether executive functioning mediates any observed association. Within a population-based Dutch birth cohort, we observed positive emotionality in 802 children using the laboratory temperament assessment battery at age 3 years. Child behavior checklist (CBCL) internalizing problems (consisting of Emotionally Reactive, Anxious/Depressed, and Withdrawn scales) were assessed at age 6 years. Parents rated their children's executive functioning at ages 4 years. Children with a lower positive emotionality at age 3 had a higher risk of withdrawn problems at age 6 years (OR = 1.20 per SD decrease in positive emotionality score, 95 % CI: 1.01, 1.42). This effect was not explained by preexisting internalizing problems. This association was partly mediated by more problems in the shifting domain of executive functioning (p < 0.001). We did not find any relation between positive emotionality and the CBCL emotionally reactive or anxious/depressed scales. Although the effect sizes were moderate, our results suggest that low levels of positive emotionality at preschool age can result in children's inflexibility and rigidity later in life. The inflexibility and rigidity are likely to affect the child's drive to engage with the environment, and thereby lead to withdrawn problems. Further research is needed to replicate these findings.

A longitudinal study of temperament continuity through IBQ, TBAQ and CBQ

The aim of this work was to study the continuity of temperament in a Spanish sample (n = 60), covering the developmental stages of infancy, toddlerhood and childhood. Temperamental dimensions showed, with few exceptions, as much homotypic as heterotypic continuity as was to be expected. At the level of latent superconstructs continuity, we found that Anger and Fear followed different developmental paths and showed continuity over all the periods evaluated. Positive Affect/Regulation superconstruct showed continuity from infancy to toddlerhood. From toddlerhood, Positive Affect/Regulation showed continuity with the superconstruct of Effortful Control but not with the superconstruct of Surgency/Extraversion. At an ipsative level, we found two groups of subjects, labeled 'nonexpressive/controlled' and 'noncontrolled/expressive'. Generally, these results confirm the stability of temperament in the periods analyzed and underline the importance of toddlerhood as a transitional period in the maturity of self-regulatory capabilities shown in childhood.