No evidence for contagious yawning in lemurs

Among some haplorhine primates, including humans, relaxed yawns spread contagiously. Such contagious yawning has been linked to social bonds and empathy in some species. However, no studies have investigated contagious yawning in strepsirhines. We conducted an experimental study of contagious yawning in strepsirhines, testing ring-tailed and ruffed lemurs (n = 24) in a paradigm similar to one that has induced contagious yawning in haplorhines. First, in a control experiment, we investigated whether lemurs responded to projected video content in general (experiment 1). We showed them two videos to which we expected differential responses: one featured a terrestrial predator and the other a caretaker holding food. Next, to test for yawn contagion, we showed individual lemurs life-size video projections of groupmates and conspecific strangers yawning, and control footage of the same individuals at rest (experiment 2). Then, to examine whether a group context might enhance or allow for contagion, we exposed subjects to the same videos in a group setting (experiment 3). Lemurs produced alarm vocalizations and moved upward while viewing the predator, but not the caretaker, demonstrating that they do perceive video content meaningfully. However, lemurs did not yawn in response to yawning stimuli when tested alone, or with their groupmates. This study provides preliminary evidence that lemurs do not respond to yawning stimuli similarly to haplorhines, and suggests that this behavior may have evolved or become more exaggerated in haplorhines after the two major primate lineages split.     

Prolonged institutional rearing is associated with atypically large amygdala volume and difficulties in emotion regulation

Early adversity, for example poor caregiving, can have profound effects on emotional development. Orphanage rearing, even in the best circumstances, lies outside of the bounds of a species-typical caregiving environment. The long-term effects of this early adversity on the neurobiological development associated with socio-emotional behaviors are not well understood. Seventy-eight children, who include those who have experienced orphanage care and a comparison group, were assessed. Magnetic resonance imaging (MRI) was used to measure volumes of whole brain and limbic structures (e.g. amygdala, hippocampus). Emotion regulation was assessed with an emotional go-nogo paradigm, and anxiety and internalizing behaviors were assessed using the Screen for Child Anxiety Related Emotional Disorders, the Child Behavior Checklist, and a structured clinical interview. Late adoption was associated with larger corrected amygdala volumes, poorer emotion regulation, and increased anxiety. Although more than 50% of the children who experienced orphanage rearing met criteria for a psychiatric disorder, with a third having an anxiety disorder, the group differences observed in amygdala volume were not driven by the presence of an anxiety disorder. The findings are consistent with previous reports describing negative effects of prolonged orphanage care on emotional behavior and with animal models that show long-term changes in the amygdala and emotional behavior following early postnatal stress. These changes in limbic circuitry may underlie residual emotional and social problems experienced by children who have been internationally adopted.     

Reaching around barriers: the performance of the great apes and 3–5-year-old children

Inhibitory control has been suggested as a key predictive measure of problem-solving skills in human and nonhuman animals. However, there has yet to be a direct comparison of the inhibitory skills of the nonhuman apes and their development in human children. We compared the inhibitory skills of all great ape species, including 3–5-year-old children in a detour-reaching task, which required subjects to avoid reaching directly for food and instead use an indirect reaching method to successfully obtain the food. We tested 22 chimpanzees, 18 bonobos, 18 orangutans, 6 gorillas and 42 children. Our sample included chimpanzees, bonobos and orangutans housed in zoos (N = 27) and others housed in sanctuaries in their native habitats (N = 37). Overall, orangutans were the most skilful apes, including human children. As expected older children outperformed younger children. Sanctuary chimpanzees and bonobos outperformed their zoo counterparts whereas there was no difference between the two orangutan samples. Most zoo chimpanzees and bonobos failed to solve the original task, but improved their performance with additional training, although the training method determined to a considerable extent the level of success that the apes achieved in a transfer phase. In general, the performance of the older children was far from perfect and comparable to some of the nonhuman apes tested.     

Psychopathy and the DSM-IV criteria for antisocial personality disorder

The Axis II Work Group of the Task Force on DSM-IV has expressed concern that antisocial personality disorder (APD) criteria are too long and cumbersome and that they focus on antisocial behaviors rather than personality traits central to traditional conceptions of psychopathy and to international criteria. We describe an alternative to the approach taken in the rev. 3rd ed. of the Diagnostic and Statistical Manual of Mental Disorders (DSM-III-R; American Psychiatric Association, 1987), namely, the revised Psychopathy Checklist. We also discuss the multisite APD field trials designed to evaluate and compare four criteria sets: the DSM-III-R criteria, a shortened list of these criteria, the criteria for dyssocial personality disorder from the 10th ed. of the International Classification of Diseases (World Health Organization, 1990), and a 10-item criteria set for psychopathic personality disorder derived from the revised Psychopathy Checklist.     

A New State-Level Index of Child Well-Being for Young Children in the U.S.

Public interest and public policy attention on the importance of cognitive and social development of young children has increased in recent years, at least in part, because scholars and researchers have found that experiences early in life have critical developmental consequences. Although scholars have generated a great deal of data on young children, relatively little is known about spatial variation in the well-being of young children. This study uses 12 indicators of child well-being to construct a comprehensive composite index of child well-being for children age 0 to 5 in each state in the United States. Examination of the 12 indicators of well-being for young children shows a high level of variation across states. The modest positive correlations among the four domains in the index suggest that they are measuring different elements of well-being. The composite index reveals that the well-being of young children follows a familiar spatial pattern, namely the well-being of young children in states located in the Deep South and the Southwest is relatively poor and the well-being of children in New England and the upper Midwest is relatively good. However, there are a several exceptions to this pattern which underscores the importance of examining the wellbeing of young children separately for all children. This study adds to a growing literature that uses an index of well-being to examine different groups of children.