Kappa (Cohen, 1960) is a popular agreement statistic used to estimate the accuracy of observers. The response of kappa to differing baserates was examined and methods for estimating the accuracy of observers presented. Results suggest that setting a single value of kappa as "minimally acceptable" (i.e., a criterion value) is not useful in ensuring…

Assessment of the neurotransmitter dopamine through measurement of the dopamine metabolite homovanillic acid (HVA) in adult subjects with mental retardation and with high rates of body stereotypy (n=12), compulsive behaviors (n=9), or neither (n=12) found lowest HVA concentrations in the stereotypy group and highest in the compulsive group. (DB)

The variability of stereotypic body-rocking motions of eight adults with severe/profound mental retardation was examined through kinematic analysis and compared to a matched nonretarded group of adults. Inter- and intra-individual variability was, on average, higher for the individuals with mental retardation. Results suggest that low variability…

The facial stereotypies of adults diagnosed as having mental retardation and tardive dyskinesia were examined through a kinematic analysis of videotaped lip and tongue movements. The high degree of movement variability found suggests that low variability of discrete properties of movement kinematics may not be a defining feature of stereotypies.…

This study of 12 residents of a treatment facility for individuals with mental retardation examined cycles in occurrences of self-injurious behavior (SIB) and aggression both within and across individuals. The study confirmed that such behavior tended to be rhythmical, with cycles of three-month and five-month periods consistently observed for…

Behavior states were observed in 66 subjects (ages 1-21) with profound disabilities, and data were analyzed as percentage of time subjects spent in various states, influence of environmental variables, and evidence of nonlinear state transitions. Findings suggest complex behavioral processes in the levels of alertness and responsiveness associated…

This analysis of nine young adult males with Down's syndrome found that subjects had great difficulty in completing a skilled motor-perceptual task. Compared to controls, they were much slower, less accurate, and achieved fewer target performances. These behavioral patterns were associated with movement-related brain macropotentials altered in…

The structure of adaptive behavior as a function of age and handicap status was investigated with 288 mentally retarded persons and nonretarded controls. Exploratory analysis of the subscale scores from the Scales of Independent Behavior revealed a large Adaptive or Personal Independence dimension and smaller Academic, Personal Responsibility, and…

The relationship between abnormal stereotyped behaviors and abnormal focused affections was examined in 20 children (ages 7-13) with developmental disabilities. Results include all children with abnormal focused affections exhibited stereotypes; abnormal focused affects could be studied reliably in this population through several methodologies;…

Relative prevalence of stereotyped behaviors was studied with 246 children and adults with developmental disabilities. Two staff members completed a 54-item checklist assessing stereotyped behaviors, abnormal focused affections, compulsions, rigidity, savant skills, and defensiveness. Factor analyses produced weak evidence for a general stereotypy…

Behavior state and environmental data were collected over a 5-hour period for approximately 66 students with profound disabilities from 21 educational settings. Results showed a strong relation between different state profiles and measures of development and consistency of state patterns across chronological age levels. Results are discussed in…

Catamenial and behavioral records of nine women with mental retardation who exhibited self-injurious behavior (SIB) were analyzed for six months. Analysis confirmed that SIB was cyclic across the menstrual cycle, with the highest frequency occurring in the early follicular and late follicular phases. (Author/JDD)

Three models of behavioral effects of genetic disorders characterized by mental retardation were compared: (1) no-specific effect model (all genetic disorders have identical behavioral outcomes); (2) totally specific model (each genetic disorder has unique outcomes); and (3) partially specific model (two or more genetic disorders share outcomes…

The study found that mentally retarded males (N=18) above 12 years of age with a fragile site on the X chromosome exhibited a highly idiosyncratic stereotypic form of gaze avoidance during greeting ceremonies. Results suggest this aberrant greeting behavior may be uniquely associated with this syndrome of mental retardation. (Author/DB)

The prevalence of compulsions in 210 adults with severe/profound mental retardation was studied. Prevalences were as follows: stereotypy (60.9 percent), self-injury (46.6 percent), and compulsion (40 percent). The occurrence of compulsions was positively associated with the occurrence of stereotypy, self-injury, and stereotypy plus self-injury.…