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…

This study examined structural characteristics and environmental variables in the stereotypic behaviors of eight individuals with developmental disabilities. Findings indicated that structural characteristics (percentage of time, bout length, and bout length variability) were highly correlated. Also, stereotyped behaviors were more likely to occur…

A study of 41 adults with mental retardation (11 with Prader-Willi syndrome and 30 with mental retardation due to other causes--13 overweight and 17 with normal weight) sought to determine differences in food preferences. While controls selected sweet food over larger quantities of unpreferred food, individuals with Prader-Willi syndrome selected…

This study compared maladaptive behavior in 23 people with Prader-Willi syndrome due to paternal deletion and in 23 age- and gender-matched subjects with maternal uniparental disomy. Controlling for IQs, the deletion cases showed significantly higher maladaptive ratings, more symptom-related distress, and more behavior problems. Findings suggest a…

A survey of the families of 62 persons with Prader-Willi syndrome examined the prevalence, topographies, and specific body locations of self-injurious behaviors. Self-injury was reported for 81% of the participants. Skin-picking was the most prevalent form with the front of the legs and head being disproportionately targeted. Incidence also varied…

A study attempted to replicate a previous study that presented reliability data from recordings of behavior state using a 13-category coding system. Replication was unsuccessful. Obtained mean percentage agreement on occurrence for individual behavior state and participants (n=34) ranged across observer pairs from 0 to 58 percent. (Contains 13…

A study of 288 students with moderate to severe mental retardation investigated the relationship between curricular activities and problem behaviors. Findings indicated a positive correlation between ratings of curricular activities (based on activities being socially functional, peer referenced, and behaviorally functional) and students'…

Chronotherapy was used to treat severe sleep problems in a girl with mental retardation. Chronotherapy involved systematically delaying the child's bedtime each night while maintaining a regular schedule during waking hours until an age-appropriate bedtime was achieved (in 11 days). Immediate improvements in the child's sleep patterns were…

This rejoinder to critiques (EC 602 213-215) of the authors' article (EC 602 212) on stereotypy and self-injury in the disabled responds to specific objections raised, including misleading statements, failure to address other existing models, misunderstandings, and need to include neurochemical factors. (DB)

Analysis of questionnaires completed by parents of young children with either Prader-Willi syndrome (N=84), Down syndrome (N=56), or typically developing (N=86), found children with Prader-Willi exhibited more compulsions, skin-picking, and tantrums than did the other groups. Discriminant analysis identified two functions (developmental milestones…

A review of the use of psychotropic medications for people with developmental disabilities is presented. Results suggest that prescribing drugs based on topographical features of the problem behavior, without considering the function the behavior serves for the individual, contributes to variability in clinical response. Functional analysis of a…

A study compared 143 girls (ages 6-14) with Rett syndrome with 85 girls with severe mental retardation on the Developmental Behavior Checklist. Girls with Rett syndrome presented more "autistic relating" and fewer antisocial behaviors. When compared to children with autism, they did not present with classic autistic behavioral features.…

A three-level model explains the emergence and maintenance of rhythmic stereotypy and self-injury in disabled individuals: Level 1, internally regulated rhythmic behaviors; Level 2, stereotypy and self-injury as adaptive responses to understimulating or overstimulating environments; and Level 3, stereotypy and self-injury as learned behaviors to…

The opioid antagonist naltrexone was administered to eight adults with severe or profound mental retardation and self-injurious behaviors. During naltrexone administration, there were fewer days with frequent head-banging and self-biting. Experimental subjects were also found to sleep significantly less than controls both before and during…

Mothers of 137 children (with or without a sibling having Down's syndrome) were interviewed regarding their child without Down's syndrome. There were no significant differences between groups regarding expectations of "typical" children, but mothers of girls with a Down's syndrome sibling reported significantly more conduct problems than did other…