TESTING SPHERICITY UNDER A MIXTURE MODEL

The robustness of Mauchly's sphericity test criterion when sampling from a mixture of two multivariate normal distributions is studied. The distribution of the sphericity test criterion when the sample covariance matrix has a non-central Wishart density of rank one is derived in terms of Meijer's G-functions; its distribution under the mixture model is then deduced. The robustness is studied by computing actual significance levels of the test under the mixture model using the critical values under the usual normal model.     

Anger Expression and Persistence in Young Children

This study investigated anger expression during toy removal (TR) in 92 young Chinese children, two to five years of age, and its relations to their persistence in responding to obstacles during two challenging tasks with highly desirable goals [TR and locked box (LB)] and one challenging task with a less desirable goal [impossible perfect circles (IPC)]. Anger expression during TR was positively associated with persistence during TR and LB but not during IPC. The results highlighted the positive effects of anger in the development of persistence.     

Anger and Approach Motivation in Infancy: Relations to Early Childhood Inhibitory Control and Behavior Problems

The relations among infant anger reactivity, approach behavior, and frontal electroencephalogram (EEG) asymmetry, and their relations to inhibitory control and behavior problems in early childhood were examined within the context of a longitudinal study of temperament. Two hundred nine infants’ anger expressions to arm restraint were observed at 4 months of age. Infants’ approach behaviors during play with an unpredictable toy and baseline frontal EEG asymmetry were assessed at 9 months of age. Inhibitory control during a Go/No‐Go task and parent report of behavior problems were evaluated at 4 years of age. High anger‐prone infants with left, but not right, frontal EEG asymmetry showed significantly more approach behaviors and less inhibitory control relative to less anger‐prone infants. Although a link between anger proneness in infancy and behavior problems in early childhood was not found, a combination of low approach behaviors and poor inhibitory control was predictive of internalizing behaviors.     

The Siting of Radioactive Waste Faculties: What Are the Effects on Communities?1

Abstract Despite literally dozens of attempts, and the expenditure of billions of dollars, efforts to site radioactive waste disposal facilities in this country have been uniformly unsuccessful. While both researchers and policymakers continue to address reasons for these failures, little attention is being given to the consequences for the communities themselves of these intensive siting battles. Using a research framework that addresses both the sources and consequences of community conflict, we examine what is happening in four different areas currently being considered as potential hosts for either a high- or a low-level radioactive waste facility. Some degree of conflict is observed in each community, although it varies from one area to another based on such differences as potential to experience economic benefits, perceptions of class and ethnic equity, and the role of extra-local players in the controversy. We conclude that current policies lead to inequitable distributions of risk that, in turn, create “fairness” questions that are important both in explaining current patterns of conflict and in anticipating long-term consequences for the affected communities.     

我的名字叫“卡奴”

左肩膀开始痛的时候，我做“卡族”正做得最潇洒最“嚣张”，恨不能市场上买两根黄瓜都刷卡。就差大街上买双鞋垫，也取出卡来对着空气刷一刷……     

The Relations between Infant Negative Reactivity,Non‐maternal Childcare,and Children's Interactions with Familiar and Unfamiliar Peers

The present study examined the influence of children's experiences during non‐maternal childcare on their behavior toward unfamiliar peers. Participants included children classified as negatively reactive at four months of age (N = 52) and children not negatively reactive (N = 61), who were further divided into those who experienced non‐maternal care and those who did not. Children were observed during childcare at 24 months of age and in the laboratory with an unfamiliar peer at 24 and 36 months of age, where their wariness, dysregulation, and social engagement were assessed. Within the negatively reactive childcare group, children's positive interactions with peers during childcare at 24 months predicted lower levels of wariness toward an unfamiliar peer at 36 months. This relation was not significant for children not classified as negatively reactive. The findings suggest that the influence of non‐maternal childcare is dependent on a child's temperament and on the nature of peer interactions during care.     

Predicting Social Wariness in Middle Childhood: The Moderating Roles of Childcare History, Maternal Personality and Maternal Behavior

Children with behavioral inhibition, a temperamental style characterized by infant distress to novelty and childhood social reticence, exhibit both continuity and discontinuity of this behavioral trait over the course of development. However, few researchers have identified factors that might be responsible for these different patterns. In the current study, childcare history, maternal personality, and maternal behavior were examined as moderators of the relations between infant temperament, preschool social reticence, and childhood social wariness. Seventy-seven children participated in this longitudinal study that began in infancy and continued into middle childhood. Maternal negative personality moderated the relation between infant temperament and childhood social wariness. In addition, maternal behavior moderated the relation between preschool social reticence and childhood social wariness. The findings suggest that a complex interplay of within-child and maternal factors affect the development of internalizing behavior in the early school years.     

Robustness of the Multiple Correlation Coefficient When Sampling From a Mixture of Two Multivariate Normal Populations

The density of the multiple correlation coefficient is derived by direct integration when the sample covariance matrix has a linear non-central distribution. Using the density, we deduce the null and non-null distribution of the multiple correlation coefficient when sampling from a mixture of two multivariate normal populations with the same covariance matrix. We also compute actual significance levels of the test of the hypothesis H_o : ρ_1·2…p = 0 versus H_a:ρ_1·2…p > 0, given the mixture model.     

Anger and Positive Reactivity in Infancy: Effects on Maternal Report of Surgency and Attention Focusing in Early Childhood

We examined two aspects of temperamental approach in early infancy, positive reactivity and anger, and their unique and combined influences on maternal reports of child surgency and attention focusing at 4 years of age. One hundred and fourteen infants were observed for their positive reactions to novel stimuli at 4 months, and their anger expressions during arm restraint at 9 months. Child surgency and attention focusing at age 4 years were assessed by maternal report. Infants who expressed more anger to restraint were rated higher in surgency during early childhood relative to infants who expressed less anger. The effects of positive reactivity to novelty on attention focusing were moderated by anger to restraint. These findings suggest that infant temperamental approach tendencies are multifaceted and have both unique and combined influences on later maternal report of attention and social behavior.