Obesity‐Related Hormones in Low‐Income Preschool‐Age Children: Implications for School Readiness

Mechanisms underlying socioeconomic disparities in school readiness and health outcomes, particularly obesity, among preschool‐aged children are complex and poorly understood. Obesity can induce changes in proteins in the circulation that contribute to the negative impact of obesity on health; such changes may relate to cognitive and emotion regulation skills important for school readiness. We investigated obesity‐related hormones, body mass index (BMI), and school readiness in a pilot study of low‐income preschoolers attending Head Start (participating in a larger parent study). We found that the adipokine leptin was related to preschoolers' BMI z‐score, the appetite‐regulating hormones ghrelin and glucagon‐like peptide 1 (GLP‐1), and pro‐inflammatory cytokines typically associated with early life stress; and that some of these obesity‐related biomarkers were in turn related to emotion regulation. Future work should evaluate how obesity may affect multiple domains of development, and consider modeling common physiological pathways related to stress, health, and school readiness.     

Associations Between Child Disabilities and Caregiver Discipline and Violence in Low‐ and Middle‐Income Countries

Using nationally representative samples of 45,964 two‐ to nine‐year‐old children and their primary caregivers in 17 developing countries, this study examined the relations between children's cognitive, language, sensory, and motor disabilities and caregivers' use of discipline and violence. Primary caregivers reported on their child's disabilities and whether they or anyone in their household had used nonviolent discipline, psychological aggression, and physical violence toward the target child and believed that using corporal punishment is necessary. Logistic regression analyses supported the hypothesis that children with disabilities are treated more harshly than children without disabilities. The findings suggest that policies and interventions are needed to work toward the United Nations' goals of ensuring that children with disabilities are protected from abuse and violence.     

Low‐Income Ethnically Diverse Children's Engagement as a Predictor of School Readiness Above Preschool Classroom Quality

This study examined whether children's observed individual engagement with teachers, peers, and tasks related to their school readiness after controlling for observed preschool classroom quality and children's baseline skills. The sample included 211 predominately low‐income, racially/ethnically diverse 4‐year‐old children in 49 preschool classrooms in one medium‐sized U.S. city. Results indicated that children's positive engagement with (a) teachers related to improved literacy skills; (b) peers related to improved language and self‐regulatory skills; and (c) tasks related to closer relationships with teachers. Children's negative engagement was associated with lower language, literacy, and self‐regulatory skills, and more conflict and closeness with teachers. Effect sizes were small to medium in magnitude, and some expected relations between positive engagement and school readiness were not found.     

Child‐Care Subsidies and School Readiness in Kindergarten

The federal child‐care subsidy program represents one of the government's largest investments in early care and education. Using data from the nationally representative Early Childhood Longitudinal Study–Birth Cohort, this study examines associations, among subsidy‐eligible families, between child‐care subsidy receipt when children are 4 years old and a range of school readiness outcomes in kindergarten (sample n ≈ 1,400). Findings suggest that subsidy receipt in preschool is not directly linked to subsequent reading or social‐emotional skills. However, subsidy receipt predicted lower math scores among children attending community‐based centers. Supplementary analyses revealed that subsidies predicted greater use of center care, but this association did not appear to affect school readiness.     

Exploring the Associations Between Delayed School Entry and Achievement in Primary and Secondary School

This research investigated whether delayed school entry was associated with higher achievement in national tests of reading and numeracy in Grades 3, 5, 7, and 9 (n = 2,823). Delayed entry was related to advantages in reading (0.14 SD) and numeracy (0.08 SD) at Grade 3, although little variance was explained (1%–2%). This slight advantage persisted for both domains in Grades 5 and 7, albeit with smaller effects. In Grade 9 there was no association between delayed entry and either reading or numeracy. Exploratory analyses with subsamples in each grade (n = 424–667) revealed no associations between delayed entry and achievement after controlling for inattention and hyperactivity, and negative associations between inattention and achievement in all grades in both domains (−0.33, −0.49 SD).     

Maternal Behavior and Socioeconomic Status Predict Longitudinal Changes in Error‐Related Negativity in Preschoolers

The development self‐regulation has been called a primary task of childhood. One system of self‐regulation, self‐monitoring, is indexed at the level of neural activity as early as preschool as the error‐related negativity (ERN). However, how context elicits developmental changes in neural processes of self‐monitoring like the ERN is not well understood. Here, socioeconomic status (SES) and parenting were tested as environmental influences on ERN development between ages 3 and 4 (N = 119). Results showed the expected increases in ERN between ages 3 and 4 only when both maternal sensitivity and SES were high. This work demonstrates the importance of considering the early environment in order to understand the development of a neural process supporting self‐regulation in young children.     

A Developmental Analysis of Caregiving Modalities Across Infancy in 38 Low‐ and Middle‐Income Countries

Caregiving is requisite to wholesome child development from the beginning of life. A cross‐sectional microgenetic analysis of six caregiving practices across the child's 1st year (0–12 months) in 42,539 families from nationally representative samples in 38 low‐ and middle‐income countries is reported. Rates of caregiving varied tremendously within and across countries. However, caregiving practices followed one of two developmental trajectories: (a) greater proportions of caregivers read, told stories, and named, counted, and drew with each additional month of infant age, and (b) proportions of caregivers who played, sang songs, and took their infants outside increased each month from birth but reached an asymptote at 4–5 months. Rates and growth functions of caregiving have implications for infant care and development.     

Growth in Precursor and Reading‐Related Skills: Do Low‐Achieving and IQ‐Discrepant Readers Develop Differently?

Poor readers who met low achievement and IQ‐discrepancy definitions of reading disability were compared with nonimpaired readers on their development of eight precursor and reading‐related skills to evaluate developmental differences prior to students’ identification as reading disabled. Results indicated no evidence for differences between the two groups of poor readers in the development of the eight skills, with three exceptions. Students in the IQ‐discrepant group demonstrated greater growth in letter sound knowledge, greater mean performance in visual‐motor integration at the beginning of first grade, and greater deceleration in rapid naming of letters. When compared to the nonimpaired group, low‐achieving readers demonstrated poorer performance and development in all skills, while the IQ‐discrepant readers demonstrated poorer performance and development in phonemic awareness, rapid naming of letters and objects, spelling, and word reading. The largely null results for comparisons between the two groups of poor readers challenges the validity of the two‐group classification of reading disabilities based on IQ‐discrepancy.     

Baseline Hypothalamic–Pituitary–Adrenal Axis and Parasympathetic Nervous System Activity Interact to Predict Executive Functions in Low‐Income Children

We examined interactions between baseline hypothalamic–pituitary–adrenal (HPA) axis and parasympathetic nervous system (PNS) activity in relation to executive functions (EF) in a sample (n = 1,005) of children in low wealth, nonurban communities at age 48 months. Salivary cortisol and respiratory sinus arrhythmia (RSA) represented baseline HPA axis and PNS activity, respectively. The interaction between RSA and cortisol predicted EF such that children with either lower RSA and lower cortisol, or higher RSA and higher cortisol had higher EF scores. These findings suggest a potential compensatory relation in which the PNS and HPA axis counterbalance each other to support cognition.     

Associations Between Sexting Behaviors and Sexual Behaviors Among Mobile Phone‐Owning Teens in Los Angeles

The implications of teen sexting for healthy development continue to concern parents, academics, and the general public. Using a probability sample of high school students (N = 1,208) aged 12–18, the prevalence of sexting, associations with sexting, and associations between sexing and sexual activity were assessed. Seventeen percent both sent and received sexts, and 24% only received sexts. Sending and receiving sexts were positively associated with each other and both behaviors were associated with having peers who sext. Lifetime reports of sexual intercourse, anal sex, oral sex, and recent unprotected sex were positively associated with reports of texting 300 or more times per day, only receiving sexts, and both sending and receiving sexts.     

Children's Cross‐Ethnic Relationships in Elementary Schools: Concurrent and Prospective Associations Between Ethnic Segregation and Social Status

This study examined whether ethnic segregation is concurrently (fall) and prospectively (fall to spring) associated with social status among 4th‐ and 5th‐grade African American and European American children (n = 713, ages 9–11 years). Segregation measures were (a) same‐ethnicity favoritism in peer affiliations and (b) cross‐ethnicity dislike. Social status measures were same‐ and cross‐ethnicity peer nominations of acceptance, rejection, and cool. Among African Americans, fall segregation predicted declines in cross‐ethnicity (European American) acceptance and same‐ethnicity rejection, and increases in same‐ethnicity acceptance and perceived coolness. For European American children, fall segregation predicted declines in cross‐ethnicity (African American) acceptance and increases in cross‐ethnicity rejection. Results indicate that segregation induces asymmetric changes in social status for African American and European American children.     

马克思分配理论与我国城乡居民收入差距问题研究

贫富差距过大对于我国而言,一直是重点问题。城乡居民收入差距不断扩大的趋势也是一项亟待解决的难题。城乡居民收入差距的扩大有很多方面的原因,包括制度、政策以及分配方式等,因此,为了防止城乡居民收入差距的再扩大化,应当从完善分配制度体系、改变固有的政策方针、提高劳动者素质等多个方面着手,切实缓解城乡居民收入差距过大的问题。     

甘肃省农村居民收入来源结构与消费的实证分析

本文利用1995—2012年甘肃农村居民收入来源与消费支出相关数据,以凯恩斯的绝对收入假说为理论基础,实证分析甘肃农村居民家庭经营收入、工资性收入、转移支付收入和财产性收入与人均生活消费支出关系,结果表明:甘肃农村居民不同来源的收入对人均生活消费支出影响是不同的,财产收入、转移支付收入对农村居民生活消费具有显著影响,家庭经营收入对农村居民生活消费影响有限,工资收入对农村居民生活消费支出没有影响。     

Response Inhibition in Preschoolers at Familial Risk for Attention Deficit Hyperactivity Disorder: A Behavioral and Electrophysiological Stop‐Signal Study

Children participating in the Ben‐Gurion Infant Development Study were assessed with a dynamic‐tracking version of the stop‐signal task at the age of 5 years. The sample consisted of 60 males. Stop‐signal reaction time (SSRT) was correlated with concurrent ratings of the child's attention deficit hyperactivity disorder (ADHD) symptoms. Paternal symptoms measured in the child's early infancy predicted the child's performance in the stop‐signal task: Paternal inattentiveness predicted SSRT, whereas hyperactivity predicted error proportion. Maternal symptoms were not correlated with the performance of the child in the task. A subsample of children, who were tested while electrophysiological brain activity was measured, showed that having higher ADHD symptomatology, especially hyperactivity, correlated with less activity in the brain areas that are usually recruited by children for successful inhibition.     

中国城镇居民收入差距与经济增长关系的实证研究

经济增长与收入差距两者之问相互影响。经济增长会促进收入分配差距的扩大,收入差距的扩大在一定程度上也会促进经济增长。缩小我国居民收入差距,要建立有效的个人收入分配调控机制,完善再分配手段;健全社会保障体系,理顺分配关系;改善城镇低收入家庭的住房条件,提高城镇低保标准;拓宽就业渠道,增加就业岗位。     

甘肃省旅游产业发展与农民收入增长协调性研究

基于甘肃省2010—2018年数据构建了旅游产业与农民收入两系统的评价指标体系和评价模型,并进行了实证分析.研究发现:旅游产业综合发展总体上呈现"N"型发展趋势;农民收入增长相对稳定;两系统之间的相互影响作用大,协调性不断提高,但尚未达到优质协调等级;农民收入增长水平相对滞后,在一定程度上遏制了旅游产业较为强劲的发展势头.因此,大力发展旅游产业时,要让广大农民群众全面参与到旅游开发中来,切实让当地农民共建共享旅游业发展成果,培育农民增收的长效机制,实现两系统的优质协调发展.     

Shyness‐Sensitivity and Social,School, and Psychological Adjustment in Urban Chinese Children: A Four‐Wave Longitudinal Study

This study examined reciprocal contributions between shyness‐sensitivity and social, school, and psychological adjustment in urban Chinese children. Longitudinal data were collected once a year from Grade 3 to Grade 6 (ages 9–12 years) for 1,171 children from multiple sources. Shyness‐sensitivity positively contributed to social, school, and psychological difficulties over time, with the most consistent effects on peer preference and loneliness. Social and school adjustment negatively contributed to the development of shyness‐sensitivity. The initial levels of shyness‐sensitivity and social and school adjustment moderated the growth of each other, mainly as a resource‐potentiating factor. The results indicate the significance of shyness‐sensitivity for adjustment and the role of adjustment in the development of shyness‐sensitivity in today's urban Chinese society.     

False‐Belief Understanding and Social Preference Over the First 2 Years of School: A Longitudinal Study

The role of false belief in establishing children's social relationships during the transition to school was examined and compared to other social cognitive constructs. One hundred and fourteen 5‐year‐olds were recruited during their 1st year of school (Time 1); 106 children were retained 1 year later. False belief, emotion expression recognition, empathy, verbal ability, and peer‐rated social preference were measured at both times. False belief at Time 1 had a direct influence on concurrent social preference, over and above the influence of emotion expression recognition and empathy. False belief made no independent contribution to later social preference accounting for stability in social preference. The role of social cognitive development is discussed with respect to how children establish and maintain their position in a peer group.