The goal of this study was to systematically examine group differences among adults with intellectual disabilities (ID), comorbid autism spectrum disorders (ASD), and epilepsy through a detailed exploration of the characteristics that these disorders present in the area of psychopathology. Previous studies indicating that individuals with ID have…

Aim: To study the development of motor speed and associated movements in participants aged 5 to 18 years for age, sex, and laterality. Method: Ten motor tasks of the Zurich Neuromotor Assessment (repetitive and alternating movements of hands and feet, repetitive and sequential finger movements, the pegboard, static and dynamic balance,…

To learn if Protestant ethic endorsement predicted intelligence controlling for the big five personality factors, 364 college students from England and the United States completed a 65-item multifaceted work ethic endorsement measure, the 50-item Wonderlic Personnel Test, and a 60-item measure of the big five personality factors. A hierarchical…

Knowledge about the functional status of the frontal cortex in infancy is limited. This study investigated the effects of polymorphisms in four dopamine system genes on performance in a task developed to assess such functioning, the Freeze-Frame task, at 9 months of age. Polymorphisms in the catechol-O-methyltransferase ("COMT") and the…

Fifty-nine healthy infants were filmed with their mothers and with a researcher at two, four, six and nine months in face-to-face play, and in toy-play at six and nine months. During toy-play at both ages, two indices of joint attention (JA)--infant bids for attention, and percent of time in shared attention--were assessed, along with other…

Atypical attention, while not a diagnostic feature, is common in individuals with autism spectrum disorders (ASD). The study of these atypicalities has recently gained in both quantity and quality, due in part to an increased focus on attentional atypicalities as one of the earliest signs of ASD in infancy. A range of attentional processes and…

Variability in achievement across learners is a hallmark of second language (L2) learning, especially in academic-based learning. The Twins Early Development Study (TEDS), based on a large, population-representative sample in the United Kingdom, provides the first opportunity to examine individual differences in second language achievement in a…

In this article, I describe studies conducted over 25 years with secondary and post-secondary L2 learners in the United States. The evidence from these studies shows that there are important connections between students' early L1 skills and their L2 aptitude and L2 proficiency and that individual differences in students' L1 skills in elementary…

This study examined correlates of mothers' value messages using mother and adolescent reports across 3 years (N =1,638 dyads). Two fundamental socialization dimensions were assessed: compassion messages (e.g., caring for others) and caution messages (e.g., being wary of others). Multilevel models revealed distinct between-person and within-person…

This investigation examines English as foreign language college interdisciplinary and intercultural differences in learning strategy use and their implications for language processing. Positivism underpins this research at the levels of ontology (standardized variables), epistemology (detachment from the subjects) and methodology, using nomothetic…

This study explored the prevalence of violent behaviors in patients who are addicted to drugs. A sample of 252 addicted patients (203 male and 49 female) who sought outpatient treatment was assessed. Information on violent behaviors, sociodemographic factors, consumption factors (assessed by the European version of the Addiction Severity Index…

A set of computer-based recreation choice experiments were run to examine the effect of expected congestion and social interactions on the decision making process. MouseTrace is a process-tracing program that recorded individual subject's information acquisitions and provided the necessary information to determine if subjects used attribute-based…

Previous event-related potential (ERP) studies have revealed that faces and words show a robust difference in the lateralization of their N170. The present study investigated the development of this differential lateralization in school-age boys. We assessed the potential role of fetal testosterone (FT) level as a factor biasing the prenatal…

Electropalatometry is a useful clinical and research tool for measuring linguapalatal contact. The goal of this study was to examine intra-speaker variability in performance. Twenty individuals spoke VCV nonsense words using a schwa in the initial position, the 15 palatal consonants, and three corner vowels, /alpha/, /i/, /u/. A variability index…

Outliers are typically regarded as data anomalies that should be discarded. However, dynamic or "innovative" outliers can be appropriately utilized to capture unusual but substantively meaningful shifts in a system's dynamics. We extend De Jong and Penzer's 1998 approach for representing outliers in single-subject state-space models to a…