Autism is currently viewed as a spectrum condition that includes strikingly different severity levels; IQ is consistently described as one of the primary aspects of the heterogeneity in autism. To investigate the possibility of more than one distinct subtype of autism based on IQ, both latent class analysis and taxometrics methods were used to…

We identified 201 individuals who obtained IQs of 85 or below in high school and participated in the Wisconsin Longitudinal Study (a prospective longitudinal study that followed sample members from age 18 through age 53). Their life course development was contrasted with their siblings who obtained IQs above 100. Life course outcomes were assessed…

The relationship between age and IQ was evaluated in a cross-sectional sample of 80 individuals with Williams syndrome (17 to 52 years). The relationship between age and WAIS-R subtest scores was such that increases and decreases in raw scores occurred at a rate sufficient to maintain stability of age-corrected scaled scores, indicating a…

Wechsler Adult Intelligence Scale-Revised subtests, as administered to 204 adults with low IQs, were factor analyzed. Solutions proved comparable to structures extracted from the normative data and to solutions based on other standardized tests for persons with low IQs. (Author)

The relation between level of intellectual functioning and risk for associated symptoms in children with autism spectrum disorder (ASD) was investigated. Cognitive ability and associated symptoms were assessed directly and/or via parent report in 74 children with ASD at 6 and 9 years of age. Participants were classified as lower and higher…

A study of 20 learning-disabled former students with intelligence quotients between 70 and 84 was conducted to examine how they fared during the transitional year after leaving high school. Most expressed serious concerns for the future as they drifted between jobs and educational programs. (Author/JDD)

We asked 27 Euro American teens ages 16 to 17 with developmental disabilities in Los Angeles to describe friendships. Eleven characteristics of friendship reported in the research literature (similarity, proximity, transcending context, companionship, reciprocity, mutuality, intimacy, support, trust/loyalty, conflict management, and stability)…

The diagnostic overshadowing bias (tendency for a diagnosis of mental retardation to overshadow a coexisting psychopathological disorder) was examined with 57 rehabilitation counselors. Diagnostic overshadowing was found with individuals with an intelligence quotient (IQ) of 58 but not with those having IQs of 70 to 80. Counselor experience with…

We examined implicit and explicit memory in adults with Williams syndrome. An age-related dissociation was found; repetition priming (reflecting implicit memory) did not show change with age, but free recall (reflecting explicit memory) was markedly reduced. We also compared the performance of adults with Williams syndrome to adults with Down…

This study examined effects of age and IQ on implicit memory in adults with mild or moderate mental retardation with (n=48) and without (n=46) Down syndrome. Although implicit memory showed an age-associated difference and IQ-associated variation in adults with mental retardation, these effects were relatively small, which supported theories…

We compared groups with and without diagnosed dementia matched on IQ, age, and presence of Down syndrome. The Dementia Scale for Down Syndrome and Dementia Questionnaire for Mentally Retarded Persons were used to assess participants. We developed two performance tasks to determine whether they were useful in separating subjects with and without…

A double-blind, placebo-controlled, crossover study of methylphenidate and different doses of fenfluramine in 30 children (ages 5-14) with mental retardation or borderline IQ and attention deficit hyperactivity disorder was conducted. Parents and teachers cited more improvement with fenfluramine; however, fenfluramine had more side effects,…

Group and individual broad ability profiles of children with mental retardation and a matched sample of children with average achievement was investigated through use of the 7 Cattell-Horn-Carroll (CHC) factor clusters from the Woodcock-Johnson III Tests of Cognitive Abilities. Results indicate that, as a group, the ranked performance of the…

People with Williams syndrome are extremely sociable, empathic, and expressive in communication. Some researchers suggest they may be especially sensitive to perceiving emotional expressions. We administered the Faces and Paralanguage subtests of the Diagnostic Analysis of Nonverbal Accuracy Scale (DANVA2), a standardized measure of emotion…

A study of 150 students, who were referred to school study teams, investigated schools' classification decisions on low IQ students with academic and behavioral problems and found a decline in the identification rates of mild mental retardation. Compliance with the Individuals with Disabilities Education Act (IDEA) is discussed. (CR)