Early Family Experiences and Neural Activity in Rural Pakistani Children: The Differential Role of Gender.

Adversity within low- and middle-income countries (LMICs) poses severe threats to neurocognitive development, which can be partially mitigated by high-quality early family experiences. Specifically, maternal scaffolding and home stimulation can buffer cognitive development in LMIC, possibly by protecting underlying neural functioning. However, the association between family experiences and neural activity remains largely unexplored in LMIC contexts. This study explored the relation of early family experiences to later cognitive skills and absolute gamma power (21-45 Hz), a neural marker linked to higher-order cognitive skills. Drawing data from the PEDS trial, a longitudinal study in rural Pakistan, we examined maternal scaffolding at 24 months and home stimulation quality at 18 months as predictors of verbal IQ, executive functions, and absolute gamma at 48 months for 105 mother-child dyads (52 girls). Maternal scaffolding interacted with gender to predict absolute gamma power, such that higher maternal scaffolding was related to higher gamma more strongly for girls. Maternal scaffolding also interacted with absolute gamma to predict executive functions, such that higher gamma was related to better executive functions only when maternal scaffolding was average to high. Individual differences in early family experiences may partially buffer the neural underpinnings of cognitive skills from adversity in LMIC.

Small-Sided Games vs. High-Intensity Interval Training on Body Composition of Female Handball Players / Juegos Reducidos vs Entrenamiento Interválico de Alta Intensidad sobre la Composición Corporal de Jugadoras de Balonmano

SUMMARY: The purpose of this study was to compare the effects of different training programs based on small-sided games (SSG) and high-intensity interval training (HIIT) on the body composition of female handball players. A total of 45 female handball players (age: 16.13±0.89 years; training experience: 6.18±1.33 years) were assigned to three groups: game group (GG; N = 15), running group (RG; N = 15), and control group (CON; N = 15). The training programs lasted eight weeks, with two training sessions per week. The GG performed three vs. three small-sided games on a 20 m x 20 m court; the RG performed 15 s HIIT running followed by 15 s of active recovery; the CON group maintained regular handball training. Regardless of the group assignment, all participants were measured for each of the following variables: Body height, body mass, fat-free mass, fat mass, muscle mass, intracellular water, and extracellular water. The results demonstrate significant differences (p0.01) in muscle mass. The GG showed significant (p<0.001) greater improvement in these body composition variables than RG and CON. Body composition variables improved with GG, moving from 2.04 % in fat mass to 1.3 % in extracellular water. In the RG, results show significant improvements (p<0.001) only in intra- and extracellular water. The CON shows improvements in fat-free mass, muscle mass, intracellular water, and extracellular water. To conclude, eight weeks of SSG in handball provide better changes in body composition compared to HIIT 15 s - 15 s and handball training alone.

El propósito de este estudio fue comparar los efectos de diferentes programas de entrenamiento basados en juegos reducidos (SSG) y entrenamiento interválico de alta intensidad (HIIT) sobre la composición corporal de jugadoras de balonmano. Un total de 45 jugadoras de balonmano (edad: 16,13 ± 0,89 años; experiencia de entrenamiento: 6,18 ± 1,33 años) fueron asignadas a tres grupos: grupo de juego (GG; N = 15), grupo de carrera (RG; N = 15) y grupo de control (CON; N = 15). Los programas de formación duraron ocho semanas, con dos sesiones de formación por semana. El GG realizó partidos reducidos de tres contra tres en una cancha de 20 x 20 m; el RG realizó 15 s de carrera HIIT seguidos de 15 s de recuperación activa; El grupo CON mantuvo un entrenamiento regular de balonmano. Independientemente de la asignación de grupo, a todos los participantes se les midió cada una de las siguientes variables: altura corporal, masa corporal, masa libre de grasa, masa grasa, masa muscular, agua intracelular y agua extracelular. Los resultados demuestran diferencias significativas (p0,01) en la masa muscular. El GG mostró una mejora significativa (p<0,001) mayor en estas variables de composición corporal que RG y CON. Las variables de composición corporal mejoraron con GG, pasando de un 2,04 % en masa grasa a un 1,3 % en agua extracelular. En el RG, los resultados mostraron mejoras significativas (p<0,001) sólo en el agua intra y extracelular. El CON indicó mejoras en la masa magra, la masa muscular, el agua intracelular y el agua extracelular. En conclusión, ocho semanas de SSG en balonmano proporcionan mejores cambios en la composición corporal en comparación con el HIIT de 15 s - 15 s y el entrenamiento de balonmano solo.

Principles for Adapting Assessments of Executive Function across Cultural Contexts.

Direct assessments of executive functions (EFs) are increasingly used in research and clinical settings, with a central assumption that they assess "universal" underlying skills. Their use is spreading globally, raising questions about the cultural appropriateness of assessments devised in Western industrialized countries. We selectively reviewed multidisciplinary evidence and theory to identify sets of cultural preferences that may be at odds with the implicit assumptions of EF assessments. These preferences relate to motivation and compliance; cultural expectations for interpersonal engagement; contextualized vs. academic thinking; cultural notions of speed and time; the willingness to be silly, be incorrect, or do the opposite; and subject-matter familiarity. In each case, we discuss how the cultural preference may be incompatible with the assumptions of assessments, and how future research and practice can address the issue. Many of the cultural preferences discussed differ between interdependent and independent cultures and between schooled and unschooled populations. Adapting testing protocols to these cultural preferences in different contexts will be important for expanding our scientific understanding of EF from the narrow slice of the human population that has participated in the research to date.

Cortisol response marks biological sensitivity to kindergartners' social hierarchies for emerging school engagement.

This longitudinal study investigated how kindergartners' position in the classroom social hierarchy and cortisol response relate to their change in school engagement across the first year of kindergarten (N = 332, M = 5.3 years, 51% boys, 41% White, 18% Black). We used naturalistic classroom observations of social hierarchy positions, laboratory-based challenges to elicit salivary cortisol response, and teacher, parent, and child reports of emotional engagement with school. Robust, clustered regression models revealed that in the fall, lower cortisol response (but not social hierarchy position) was associated with greater school engagement. However, by spring, significant interactions emerged. Highly reactive, subordinate children showed increases in school engagement from fall to spring of the kindergarten year, whereas highly reactive, dominant children showed decreases in school engagement. This is some of the first evidence that higher cortisol response marks biological sensitivity to early peer-based social contexts.

Pakistani preschoolers' number of older siblings and cognitive skills: Moderations by home stimulation and gender.

The present study examines the link between children's number of older siblings and their cognitive development, as measured by executive function (EFs) skills and verbal skills (VIQ) in a sample of 1,302 4-year-old children (54% boys) living in rural Pakistan. Specifically, we investigate whether the links between the number of older siblings and preschoolers' EFs and VIQ are moderated by preschoolers' quality of home stimulation and gender. Multivariate regressions revealed that the number of older siblings was positively associated with EFs for boys in homes with both higher and lower levels of stimulation, and for girls in homes with lower levels of stimulation (p < .05). However, the number of older siblings was negatively associated with EFs for girls from homes with higher levels of stimulation (p = .03). Further, the number of older siblings was positively associated with VIQ in homes with lower stimulation (p < .05), but not for higher stimulation homes. Gender was not a statistically significant moderator of the association between the number of older siblings and VIQ. Findings suggest that living with more older siblings may promote emerging EFs and VIQ among boys and girls with fewer opportunities for cognitive stimulation. However, more older siblings may hinder EF development for girls in the context of adequate home stimulation, perhaps due to inequitable allocation of resources among boys and girls in more affluent, larger families. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Physical activity before and during the COVID-19 pandemic in Vojvodina, Serbia.

Background: The physical activity (PA) of the youth and adult population underwent changes during the last 2 years due to the coronavirus (COVID-19) pandemic, and all for the purpose of maintaining the health of the population. The purpose of this study was to estimate the levels of PA in the youth population and the adult population (young and old) during the COVID-19 pandemic in the territory of Vojvodina, Serbia, and to determine the differences between them, as well as to compare these results with the results before the pandemic. Methods: A total of 1,117 subjects (age 36.27 ± 15.08 years) from the territory of Vojvodina, Serbia, participated in the study. Subjects were recruited and assigned to one of the three groups according to their age: youth group (N = 395; age 18-24 years), young adults group (N = 347; from 25 to 44 years), and old adults group (N = 375; age 45-65 years). All participants in this study completed the International Physical Activity Questionnaire Short-Form between July and November 2021, during the fourth wave of the COVID-19 pandemic in Vojvodina, Serbia. The Kruskal-Wallis test and Dunn multiple comparison post-hoc method were used for statistical analyses. Results: The youth showed the highest result in total weekly energy expenditure (3,893.72 ± 2,010.01 MET-min/week) compared to young adults (2,528.20 ± 1,804.11 MET-min/week) and old adults (2,369.07 ± 2,084.95 MET-min/week) during the COVID-19 pandemic in Vojvodina, Serbia. In addition, adults (young and old) spent more time sitting than youth during the same period. Furthermore, the youth achieved greater results in levels of PA during the COVID-19 pandemic compared to the situation before the COVID-19 pandemic. However, adult populations achieved lower results during the COVID-19 pandemic than before the COVID-19 pandemic. Conclusion: During the COVID-19 pandemic, the youth from Vojovida, Serbia, achieved greater results in PA levels than the adult populations. Based on that, we recommend that it is necessary to take steps toward increasing PA in the adult population, especially old adults.

The unique relevance of executive functions and self-regulation behaviors for understanding early childhood experiences and preschoolers' outcomes in rural Pakistan.

Performance-based measures of children's executive functions (EFs) do not capture children's application of these skills during everyday emotionally-laden and socially-mediated interactions. The current study demonstrates the value of using assessor report of self-regulation behaviors (inhibitory control and positive affect/engagement) in addition to EF tasks when studying early childhood experiences and development in a rural lower-middle-income country setting. In a sample of 1302 disadvantaged 4-year-olds living in rural Pakistan, we found that directly assessed EFs were significantly related to assessor observations of children's inhibitory control and positive affect/engagement during a structured assessment protocol. However, EFs and two types of self-regulation behaviors demonstrated unique associations with children's (1) contextual experiences, as indexed by family socio-economic resources, participation in parenting interventions, and children's physical growth; and (2) age-salient developmental outcomes, as indexed by direct assessment of pre-academic skills and maternal report of prosocial behaviors and behavior problems. First, family wealth uniquely predicted only observed positive affect/engagement, whereas maternal education uniquely predicted only EFs. Second, children's antecedent linear growth was a significant predictor of both EFs and positive affect/engagement, but exposure to an enhanced nutrition intervention during the first 2 years of life and preschoolers' hair cortisol concentration were associated only with observed self-regulation behaviors. Finally, both EFs and observed positive affect/engagement uniquely predicted children's pre-academic skills. In contrast, only assessors' ratings of positive affect/engagement uniquely predicted maternal report of prosocial behaviors and only assessors' ratings of inhibitory control uniquely predicted maternal report of behavioral problems.

Executive function mediates the association between cumulative risk and learning in Ghanaian schoolchildren.

Research on the associations among adversity, executive function (EF), and academic outcomes in low- and middle-income countries, where developmental risk factors are more prevalent and impoverished environments are more widespread than in high income countries, is sparse. This study examines the relations among cumulative risk, EF, and learning outcomes measured 2-years later in Ghanaian third- and fourth-graders (N = 371; 49% female), shedding light on underlying mechanisms of how risk can undermine learning. A cumulative risk index was created based on a set of four child-reported risk factors: home aggression, unsafe home neighborhood, hunger, and having worked for pay. Cumulative risk and EF were negatively correlated. Learning outcomes (literacy and math test scores) were negatively correlated with earlier measures of cumulative risk and positively correlated with earlier measures of EF. EF mediated the association between cumulative risk and later learning outcomes, accounting for 65.3% of the total effect for literacy and 100% for math. This mediated pathway was robust to controls for child and household sociodemographic characteristics. The findings contribute to a small evidence base on the mediating role of EF in linking adversity and learning outcomes in a global context. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Taking a few deep breaths significantly reduces children's physiological arousal in everyday settings: Results of a preregistered video intervention.

This preregistered, randomized field experiment tested the effectiveness of a brief deep breathing intervention on children's concurrent physiological arousal in naturalistic settings (N  = 342; Mage  = 7.48 years; 46% female; 53% Asian, 26% White; 21% other race/ethnicity). The treatment consisted of an animated video that introduced deep breathing as a self-regulation strategy and scaffolded the child in taking a few slow-paced breaths, while the control group watched an informational video featuring similar animated images. Respiratory sinus arrhythmia (RSA) and heart rate (HR) were measured while children were sitting still (baseline) and subsequently while watching 1-min videos. Relative to baseline arousal, RSA increased and HR decreased only in response to the deep-breathing treatment video. Effects were larger in the second 30-s epoch of the video, which included most of the deep breathing practice. RSA fully mediated the intervention's effects on HR. By analyzing all children exposed to intervention video regardless of their engagement in the deep breathing practice (intention-to-treat design) and by using easily scalable treatment videos, the study identifies an effective and pragmatic approach to reducing children's physiological arousal in everyday, group settings. Implications for advancing applied developmental psychophysiological research are discussed.

Parent-child physiological synchrony: Concurrent and lagged effects during dyadic laboratory interaction.

This study investigated whether parents and kindergarten children show concurrent and time-lagged physiological synchrony during dyadic interaction. Further, we tested whether parent-child behavioral co-regulation was associated with concurrent and time-lagged synchrony, and whether synchrony varied by the type of interaction task. Participants were 94 children (Mage  = 5.6 years, 56% female) and their parents. We simultaneously measured parent and child respiratory sinus arrhythmia (RSA) during four dyadic interaction tasks: free play, clean up, problem-solving, and puzzle teaching. We found that synchrony varied by task. Concurrent synchrony occurred only during the puzzle teaching task, such that parent and child RSA were significantly and positively associated with each other simultaneously. Time-lagged synchrony occurred only during the problem-solving task, such that parent RSA was positively associated with child RSA 30 seconds later, and child RSA was negatively associated with parent RSA 30 seconds later. Although behavioral co-regulation and physiological synchrony have been conceptualized as markers of responsive parent-child interactions, our study finds no evidence that physiological synchrony is associated with between-dyad differences in behavioral co-regulation.

Effects of small-sided games and high-intensity interval training on physical performance in young female handball players.

This study was designed to compare the effectiveness of small-sided handball games in combination with handball training (SSG group) versus high-intensity interval training in combination with handball training (HIIT group) on physical performance of young female handball players during pre-competitive period. Twenty-four young female handball players, who have a 6.17 ± 1.54 years training experience and competition in the national league participated in this study. SSG group (n = 12; age 16.06 ± 0.80 years, body mass 61.27 ± 3.68 kg, body height 1.64 ± 4.7 m, body mass index 22.7 kg/m2) while HIIT group (n = 12; 16.20 ± 1.28 years, body mass 62.46 ± 7.86 kg, body height 1.68 ± 6.8 m, body mass index 22 kg/m2). Both groups applied training programs twice-a-week for 8 weeks. Before and after the training programs physical performances were assessed: Countermovement jump (CMJ), Squat jump (SJ), Sprint on 0-10 m; Sprint on 0-20 m; Sprint on 0-30 m, Throwing medicine ball and total distance covered during the Yo-YoIRT1. After 8 weeks SSG and HIIT groups significantly improved CMJ, SJ, 0-20 m sprint, 0-30 m sprint, throwing medicine ball and Yo-YoIRT1 (p ≤ 0.05). However, significantly greater improvement was achieved in Yo-YoIRT1 (m) in HIIT group (28.40%) than SSG group (17.63%). These results indicate that SSG group and HIIT group equally improve of physical performances (jump, sprint and upper explosive strength) among young female handball players in pre-competitive period.

Early and concurrent home stimulation: Unique and indirect links with fine motor skills among 4-year-old children in rural Pakistan.

Fine motor skills enable children to make precise and coordinated movements with their hands and support their ability to engage in everyday activities and learning experiences. In a longitudinal study of 1,058 4-year-old children in rural Pakistan (n = 488 girls), we examined how prior and concurrent levels of home stimulation relate to change in fine motor skills from ages 2 to 4 while controlling for family wealth, maternal education, number of siblings at birth, prior and concurrent measures of children's physical growth and food insecurity, and prior motor skills at age 2. Moreover, we tested whether the association between early home stimulation and subsequent fine motor skills was mediated by physical growth, food insecurity, motor skills at age 2, and concurrent home stimulation. Results revealed that home stimulation at 18 months was positively associated with change in fine motor skills from ages 2 to 4, over and above family socioeconomic resources. This association was mediated by physical growth, food insecurity and motor skills at age 2. In contrast to home stimulation at 18 months, home stimulation at age 4 was positively associated with concurrent motor skills at age 4 when controlling for all antecedent family factors, as well as prior and concurrent measures of physical growth and food insecurity, and prior motor skills at age 2. Findings suggest that the preschool period may be an important window of time when physically and cognitively stimulating experiences at home uniquely relate to variability in fine motor development. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Evaluating motor performance with the Bruininks-Oseretsky Test of motor proficiency in impoverished Pakistani children.

OBJECTIVE: To evaluate the sensitivity of the modified Brief Form of Bruininks Oseretsky Test in identifying motor differences secondary to malnutrition and poverty. METHODS: This longitudinal cohort study was conducted at Nowshero Feroze, Sindh from 2013 to 2014 and comprised data drawn from children who participated in a randomised controlled trial, that assessed responsive stimulation and nutrition interventions in the first two years of life. Outcome measures included motor development assessed using Brief Form of Bruininks Oseretsky Test, child anthropometry and household economic and demographic information. Data was analysed using SPSS 15 and STATA 12. RESULTS: Of the 1058 children, 570(53%) were boys. Moderate-severe stunting was reported in 171(16.12%) subjects, while moderate-severe underweight was reported in 117(11.1%). Also, 591(56%) subjects belonged to poor families, 343(32%) had illiterate mothers, and 392(37%) were food-insecure. Malnutrition, socio-economic status and maternal literacy were significantly associated with a 6-item motor composite of the Brief Form of Bruininks Oseretsky Test (p<0.05). CONCLUSIONS: The 6-item motor composite of the Brief Form of Bruininks Oseretsky Test was found to be a reliable tool to measure motor performance in Pakistani pre-school children.

Physical Activity of Serbian Children in Daycare.

BACKGROUND: Monitoring of physical activity within the educational institution is of great importance, primarily because of the orientation and content implemented in the daycare. This research aimed to examine the number of steps children took during their stay in daycare with regards to age, gender and the frequency of going out. METHODS: The research was conducted in four daycares in the urban environment of Novi Sad (Republic of Serbia), where 231 children, aged 5 to 7, were monitored (129 boys and 102 girls). Data on the number of steps were obtained using the pedometers. RESULTS: The result of the univariate analysis of the variance test confirmed a statistically significant difference in the number of steps in relation to the age of children (p = 0.04). Boys were more active than girls in both age groups (p = 0.001). Children who were going to the daycare yard three to five times a week took drastically more steps than children who went up to twice a week (p = 0.001). CONCLUSION: The results of the current study show that age, gender, and time spent outdoors are significant determinants of physical activity in preschool age. Therefore, interventions regarding physical activity should be made during early childhood in order to promote health and prevent disease.

Learning to let go: Parental over-engagement predicts poorer self-regulation in kindergartners.

Responsive parenting and parental scaffolding have been shown to foster executive functions (EFs) and self-regulation skills in young children, but could too much parental directive engagement be counterproductive? To answer this question, we examined parental responses when children were demonstrating active on-task behaviors in a community sample of 102 dyads. We measured the time that parents spend actively guiding children's behavior relative to following the child's lead and created a measure of parental over-engagement to index the degree of active parental engagement via positive control/scaffolding behaviors. We hypothesized that parental over-engagement would negatively relate to children's self-regulation and EF skills because it creates fewer opportunities for children to practice self-regulation by leading dyadic interaction with their parents. We used an innovative State-Space Grid method to capture second-to-second changes in parental and child behaviors during a set of structured tasks. We examined the conceptual overlap of over-engagement with the global ratings of parenting, revealing that parental over-engagement was negatively correlated with global ratings of parental scaffolding and unrelated to global ratings of parental sensitivity. Next, we showed that parental over-engagement predicted lower levels of child hot EFs and observed self-regulation, controlling for age, parent education, family income, and global ratings of parenting. The predictive validity of over-engagement was unique to times when the child was actively engaged and was absent when the child was passively engaged. This study contributes to the discussion of how parents can support the development of self-regulation during the transition to elementary school. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Moving beyond executive functions: Challenge preference as a predictor of academic achievement in elementary school.

Intrinsic motivation and executive functions (EFs) have been independently studied as predictors of academic achievement in elementary school. The goal of this investigation was to understand how students' challenge preference (CP), an aspect of intrinsic motivation, is related to academic achievement while accounting for EFs as a confounding variable. Using data from a longitudinal study of 569 third-, fourth-, and fifth-graders (50% female), we tested students' self-reported CP as a predictor of mathematics and English language arts (ELA) achievement in multilevel models that controlled for school fixed effects and student demographic characteristics. CP was positively associated with mathematics and ELA over and above the set of covariates and EFs. While also controlling for prior achievement, CP continued to explain a small amount of unique variance in mathematics, but not in ELA. These results underscore the importance of including measures of students' intrinsic motivation, in addition to EFs, to obtain a comprehensive understanding of academic success.

Biological sensitivity to context in Pakistani preschoolers: Hair cortisol and family wealth are interactively associated with girls' cognitive skills.

Many young children in low- and middle-income countries (LMICs) face heightened risk for experiencing environmental adversity, which is linked with poorer developmental outcomes. Children's stress physiology can shed light on why children are differentially susceptible to adversity. However, no known studies have examined whether links between adversity and children's development are moderated by children's stress physiology in LMICs. The present study revealed significant interactive effects of hair cortisol concentrations, an index of chronic physiological stress regulation, and family wealth on preschoolers' cognitive skills in rural Pakistan. In a sample of 535 4-year-old children (n = 342 girls), we found significant associations between family wealth and direct assessments of verbal intelligence, pre-academic skills, and executive functions only in girls with lower hair cortisol concentrations. Specifically, girls with lower cortisol concentrations displayed greater cognitive skills if they came from relatively wealthier families, but lower cognitive skills if they came from very poor families. There were no significant associations among boys. Results provide evidence of biological sensitivity to context among young girls in a LMIC, perhaps reflecting, in part, sex differences in daily experiences of environmental adversity.

The effects of leucine and whey protein supplementation with eight weeks of resistance training on strength and body composition.

BACKGROUND: In past few decades, supplementation has become very popular within professional and recreational athletes. Most interested among supplements are protein and amino acids. Therefore, the purpose of this study was to examine the effects of leucine supplementation in comparison to whey protein supplementation with placebo group on strength and body composition during 8 weeks of resistance training program. METHODS: Thirty male college athletes (mean age±SD =23.92±1.54 years) participated in this investigation and were randomly assigned to one of three groups: whey protein (WP, N.=10), leucine (LEU, N.=10) or placebo (PLA, N.=10). The WP, LEU and PLA performed resistance training for 8 weeks. Strength (1RM bench press, squat, shoulder press) and maximum pull-ups and body composition has been assessed and data was analyzed with mixed-design analysis of variance (P≤0.01). RESULTS: The WP group achieved significantly greater (P≤0.01) increases in 1RM bench press than the LEU and PLA groups (+16 kg for WP; + 7.5 kg for LEU and + 5 kg for PLA). The LEU group achieved significantly greater gains (P≤0.01) in fat free mass, muscle mass and significantly decreases (P≤0.01) in fat mass compared to WP and PLA groups. CONCLUSIONS: Whey protein supplementation in male collegiate athletes during resistance training achieved greater increase in strength than leucine and placebo groups, and leucine group achieved significantly greater improvement in body composition than whey protein and placebo groups.

Addressing educational inequalities and promoting learning through studies of stress physiology in elementary school students.

To be ready to learn, children need to be focused, engaged, and able to bounce back from setbacks. However, many children come to school with heightened or diminished physiological arousal due to exposure to poverty-related risks. While stress physiology plays a role in explaining how adversity relates to processes that support students' cognitive development, there is a lack of studies of physiological stress response in educational settings. This review integrates relevant studies and offers future directions for research on the role of stress physiology in the school adaptation of elementary school students, focusing on these important questions: (a) What are the links between physiological stress response and learning-related skills and behaviors, and do they vary as a function of proximal and distal experiences outside of school? (b) How are school experiences associated with students' physiological stress response and related cognitive and behavioral adaptations? (c) How can we leverage measures of students' physiological stress response in evaluations of school-based interventions to better support the school success of every student? We hope to stimulate a new wave of research that will advance the science of developmental stress physiology, as well as improve the application of these findings in educational policy and practice.

Introduction to special issue on global child development studies.

As global child development research is taking off, this special issue provides a collection of recent research characterizing child development across the globe, validating behavioral and neuroimaging tools across diverse geographical setting and cultures, exploring relationships between risk and protective factors and diverse child outcomes, and testing novel avenues of innovative intervention. In particular, three prominent themes that emerge from this special issue are (a) research linking biology and behavior in the service of uncovering biological systems that are susceptible to experience and may mediate associations between experiences and long-term developmental outcomes in global child development research, (b) a movement towards inclusion of more detailed investigation of children's socio-emotional functions in global child development research, and (c) longitudinal studies of developmental outcomes across global settings. In this introduction we outline key themes and findings from the 25 articles included in the special issue.