Identifying shared environmental contributions to early substance use: the respective roles of peers and parents

Although behavior genetic studies have suggested that early substance use is primarily environmentally mediated, no study has sought to identify the specific sources of environmental variance. Using data obtained from multiple informants, this study assessed the contributions of peer deviance and parent-child relationship problems to substance use in 14-year-old male and female twins (N = 1,403) drawn from the Minnesota Twin Family Study (MTFS). All three phenotypes were influenced primarily by shared environmental variance (average c(2) =.51), as was the overlap among them. Moreover, peer deviance and parent-child relationship problems accounted for approximately 77% of the variance in early substance use. Findings also indicated that peer deviance, but not parent-child relationship problems, accounted uniquely for variance in early substance use.     

Teachers' screening for attention deficit/hyperactivity disorder: comparing multinational samples on teacher ratings of ADHD

This study evaluates a measurement model for Attention Deficit/Hyperactivity Disorder (ADHD). The DSM-IV divides 18 symptoms into two groups, inattentive and hyperactive/impulsive. Elementary school teachers rated 21,161 children in 4 locations: Spain, Germany, urban US, and suburban US. Confirmatory factor analysis suggested that the 2-factor model (inattention, hyperactivity/impulsivity) shows the best fit. A third factor, impulsivity, was too slight to stand-alone. Children with academic performance problems were distinguished by inattention, but children with behavior problems typically had elevations in inattention, hyperactivity, and impulsivity. Between-site differences were statistically significant, but so small that we conclude that same measurement model fits all 4 samples in 2 continents.     

Selecting the wrong processor: a critique of Leslie’s theory of mind mechanism–selection processor theory

The fundamental assumption behind Leslie’s theory of mind mechanism theory is that from 18 months onwards a single device, the theory of mind mechanism, allows children to represent both pretend and belief in terms of propositional attitudes. This is compared with Perner’s argument that early pretence is not understood in terms of propositional attitudes. Recent modifications to Leslie’s theory aim to explain why children younger than 4 years fail the false belief test. Leslie argues that the correct proposition is computed, not by the theory of mind mechanism, but by the selection processor, a later-developing executive device. In this paper I examine the coherence of Leslie’s revised theory and conclude that representing beliefs is now entirely the task of the selection processor; the theory of mind mechanism is no longer involved, thus contravening the fundamental assumption of the theory. The conclusion is that the theory and the assumption should be abandoned.     

Professional efficacy,exhaustion, and work characteristics among police officers: A longitudinal test of the learning‐related predictions of the demand—control model

The present study addressed the relationships among professional efficacy, emotional exhaustion, and job characteristics (job demands and job control) in the context of a two‐wave panel study among 828 Dutch police officers. Based on the demand–control model, we expected that high demands/high control would be positively related to professional efficacy, and that high demands/low control would be related to high levels of exhaustion. Moreover, we hypothesized that high levels of exhaustion would lead to lower levels of professional efficacy and that high levels of efficacy would lead to low levels of exhaustion. Structural equation modelling largely supported these predictions. High demands were longitudinally related to high levels of efficacy and high levels of exhaustion; high control was longitudinally related to high levels of efficacy. Further, efficacy and exhaustion were indeed mutually related. Finally, high levels of exhaustion were longitudinally related to high levels of demands. We conclude that there are complex, yet theoretically, and practically interpretable relations among efficacy, strain and work characteristics.     

Age differences in verbal and visuo-spatial working memory updating: evidence from analysis of serial position curves

Memory updating is the ability to select and update relevant information and suppress no-longer-relevant data. The few studies in this area, targeting mainly the verbal domain, have investigated and confirmed an age-related decline in working memory updating ability (De Beni & Palladino, 2004; Van der Linden, Bredart, & Beerten, 1994). The present research examines the ability of younger and older adults to update information in verbal and visuo-spatial running memory tasks. Results showed that the participants' performance was higher in the verbal than in the visuo-spatial task. Nonetheless, independently of the task domain, an age-related decline in updating performance was found. Moreover, analysis of serial positions suggested that, in the updating procedure, the participants were not attempting to actively maintain items, preferring to adopt a low-effort, "recency-based" strategy. The use of this type of strategy is more evident in older participants, as shown in both the accuracy performance and the proportion of intrusion errors.     

Access to environmental stimulation via eyelid responses for persons with acquired brain injury and multiple disabilities: a new microswitch arrangement

This study assessed a new microswitch arrangement for eyelid responses using an optic sensor placed above the cheekbone and a small sticker on the person's eyelid. This new arrangement, which was designed to avoid interference of the microswitch with the person's visual functioning, was tested on three adults with acquired brain injury and multiple (consciousness, communication, and motor) disabilities. The study was carried out according to a non-concurrent multiple baseline design across participants. Data showed the new microswitch arrangement was suitable for all three participants, who increased their responding during the intervention phase of the study when their responses allowed them to access preferred stimulation. Practical implications of the findings are discussed.     

Grey parrot number acquisition: The inference of cardinal value from ordinal position on the numeral list

A Grey parrot (Psittacus erithacus) had previously been taught to use English count words ("one" through "sih" [six]) to label sets of one to six individual items (Pepperberg, 1994). He had also been taught to use the same count words to label the Arabic numerals 1 through 6. Without training, he inferred the relationship between the Arabic numerals and the sets of objects (Pepperberg, 2006b). In the present study, he was then trained to label vocally the Arabic numerals 7 and 8 ("sih-none", "eight", respectively) and to order these Arabic numerals with respect to the numeral 6. He subsequently inferred the ordinality of 7 and 8 with respect to the smaller numerals and he inferred use of the appropriate label for the cardinal values of seven and eight items. These data suggest that he constructed the cardinal meanings of "seven" ("sih-none") and "eight" from his knowledge of the cardinal meanings of one through six, together with the place of "seven" ("sih-none") and "eight" in the ordered count list.     

Author Correction: Assessing Adolescents’ Information Management with Mothers and Fathers: A Brief Report

Journal of Child and Family Studies -