"Age of onset of marijuana use and executive function": Correction to Gruber et al. (2011)

Reports an error in "Age of onset of marijuana use and executive function" by Staci A. Gruber, Kelly A. Sagar, Mary Kathryn Dahlgren, Megan Racine and Scott E. Lukas (Psychology of Addictive Behaviors, Advanced Online Publication, Nov 21, 2011, np). Figure 1 should have been presented in color. All versions of this article have been corrected. (The following abstract of the original article appeared in record 2011-27123-001.) Marijuana (MJ) remains the most widely abused illicit substance in the United States, and in recent years, a decline in perceived risk of MJ use has been accompanied by a simultaneous increase in rates of use among adolescents. In this study, the authors hypothesized that chronic MJ smokers would perform cognitive tasks, specifically those that require executive function, more poorly than control subjects and that individuals who started smoking MJ regularly prior to age 16 (early onset) would have more difficulty than those who started after age 16 (late onset). Thirty-four chronic, heavy MJ smokers separated into early and late onset groups, and 28 non-MJ smoking controls completed a battery of neurocognitive measures. As hypothesized, MJ smokers performed more poorly than controls on several measures of executive function. Age of onset analyses revealed that these between-group differences were largely attributed to the early onset group, who were also shown to smoke twice as often and nearly 3 times as much MJ per week relative to the late onset smokers. Age of onset, frequency, and magnitude of MJ use were all shown to impact cognitive performance. Findings suggest that earlier MJ onset is related to poorer cognitive function and increased frequency and magnitude of MJ use relative to later MJ onset. Exposure to MJ during a period of neurodevelopmental vulnerability, such as adolescence, may result in altered brain development and enduring neuropsychological changes. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Risky Business: Risk Perception and the Use of Medical Services among Customers of DTC Personal Genetic Testing

Direct-to-consumer genetic testing has generated speculation about how customers will interpret results and how these interpretations will influence healthcare use and behavior; however, few empirical data on these topics exist. We conducted an online survey of DTC customers of 23andMe, deCODEme, and Navigenics to begin to address these questions. Random samples of U.S. DTC customers were invited to participate. Survey topics included demographics, perceptions of two sample DTC results, and health behaviors following DTC testing. Of 3,167 DTC customers invited, 33% (n?=?1,048) completed the survey. Forty-three percent of respondents had sought additional information about a health condition tested; 28% had discussed their results with a healthcare professional; and 9% had followed up with additional lab tests. Sixteen percent of respondents had changed a medication or supplement regimen, and one-third said they were being more careful about their diet. Many of these health-related behaviors were significantly associated with responses to a question that asked how participants would perceive their colon cancer risk (as low, moderate, or high) if they received a test result showing an 11% lifetime risk, as compared to 5% risk in the general population. Respondents who would consider themselves to be at high risk for colon cancer were significantly more likely to have sought information about a disease (p?=?0.03), discussed results with a physician (p?=?0.05), changed their diet (p?=?0.02), and started exercising more (p?=?0.01). Participants’ personal health contexts—including personal and family history of disease and quality of self-perceived health—were also associated with health-related behaviors after testing. Subjective interpretations of genetic risk data and personal context appear to be related to health behaviors among DTC customers. Sharing DTC test results with healthcare professionals may add perceived utility to the tests.     

Model selection and psychological theory: a discussion of the differences between the Akaike information criterion (AIC) and the Bayesian information criterion (BIC)

This article reviews the Akaike information criterion (AIC) and the Bayesian information criterion (BIC) in model selection and the appraisal of psychological theory. The focus is on latent variable models, given their growing use in theory testing and construction. Theoretical statistical results in regression are discussed, and more important issues are illustrated with novel simulations involving latent variable models including factor analysis, latent profile analysis, and factor mixture models. Asymptotically, the BIC is consistent, in that it will select the true model if, among other assumptions, the true model is among the candidate models considered. The AIC is not consistent under these circumstances. When the true model is not in the candidate model set the AIC is efficient, in that it will asymptotically choose whichever model minimizes the mean squared error of prediction/estimation. The BIC is not efficient under these circumstances. Unlike the BIC, the AIC also has a minimax property, in that it can minimize the maximum possible risk in finite sample sizes. In sum, the AIC and BIC have quite different properties that require different assumptions, and applied researchers and methodologists alike will benefit from improved understanding of the asymptotic and finite-sample behavior of these criteria. The ultimate decision to use the AIC or BIC depends on many factors, including the loss function employed, the study's methodological design, the substantive research question, and the notion of a true model and its applicability to the study at hand.     

False-belief understanding in 2.5-year-olds: evidence from two novel verbal spontaneous-response tasks

Recent research indicates that toddlers and infants succeed at various non-verbal spontaneous-response false-belief tasks; here we asked whether toddlers would also succeed at verbal spontaneous-response false-belief tasks that imposed significant linguistic demands. We tested 2.5-year-olds using two novel tasks: a preferential-looking task in which children listened to a false-belief story while looking at a picture book (with matching and non-matching pictures), and a violation-of-expectation task in which children watched an adult 'Subject' answer (correctly or incorrectly) a standard false-belief question. Positive results were obtained with both tasks, despite their linguistic demands. These results (1) support the distinction between spontaneous- and elicited-response tasks by showing that toddlers succeed at verbal false-belief tasks that do not require them to answer direct questions about agents' false beliefs, (2) reinforce claims of robust continuity in early false-belief understanding as assessed by spontaneous-response tasks, and (3) provide researchers with new experimental tasks for exploring early false-belief understanding in neurotypical and autistic populations.     

The six most essential questions in psychiatric diagnosis: a pluralogue part 1: conceptual and definitional issues in psychiatric diagnosis

In face of the multiple controversies surrounding the DSM process in general and the development of DSM-5 in particular, we have organized a discussion around what we consider six essential questions in further work on the DSM. The six questions involve: 1) the nature of a mental disorder; 2) the definition of mental disorder; 3) the issue of whether, in the current state of psychiatric science, DSM-5 should assume a cautious, conservative posture or an assertive, transformative posture; 4) the role of pragmatic considerations in the construction of DSM-5; 5) the issue of utility of the DSM - whether DSM-III and IV have been designed more for clinicians or researchers, and how this conflict should be dealt with in the new manual; and 6) the possibility and advisability, given all the problems with DSM-III and IV, of designing a different diagnostic system. Part I of this article will take up the first two questions. With the first question, invited commentators express a range of opinion regarding the nature of psychiatric disorders, loosely divided into a realist position that the diagnostic categories represent real diseases that we can accurately name and know with our perceptual abilities, a middle, nominalist position that psychiatric disorders do exist in the real world but that our diagnostic categories are constructs that may or may not accurately represent the disorders out there, and finally a purely constructivist position that the diagnostic categories are simply constructs with no evidence of psychiatric disorders in the real world. The second question again offers a range of opinion as to how we should define a mental or psychiatric disorder, including the possibility that we should not try to formulate a definition. The general introduction, as well as the introductions and conclusions for the specific questions, are written by James Phillips, and the responses to commentaries are written by Allen Frances.     

Doing as they would do: How the perceived ethical preferences of third-party beneficiaries impact ethical decision-making

Although unethical behavior often benefits third-parties not directly complicit in the misconduct, not all beneficiaries welcome these ill-gotten benefits. We investigate whether actors consider the ethical preferences of potential beneficiaries or rely solely on their own ethical predispositions when making decisions that affect others. Three studies demonstrate that the perceived ethical preferences of these beneficiaries can substantially influence the likelihood that actors behave unethically on their behalves. These studies show that actors consider the ethical preferences of beneficiaries only when their own ethical disposition is outcome-based.     

Screening for Psychopathy: Validation of the Psychopathic Personality Inventory-Short Form with Reference Scores

The current study reports validation results for the Psychopathic Personality Inventory (PPI) and its subscales, and for a newly developed PPI-Short Form (PPI-SF) in forensic and non-forensic populations. We also provide criterion reference scores for the PPI and the PPI-SF. In Study 1, we used PPI data from 1,065 participants and supplementary PCL-R data from a subsample of 91 forensic offenders. Mokken scale analysis was used to construct the PPI-SF. In Study 2, PPI-SF and PCL-R data were collected from 60 participants. The study yielded promising but preliminary support for the construct validity of the PPI and the PPI-SF. The PPI-SF is of interest for risk assessment because of its (a) strong relationship with the PCL-R total score and (b) subscales known for their predictive value for violence and criminal recidivism.     

New Directions in Sales Leadership Research

The changing environment facing sales organizations is characterized by the dimensions of complexity, collaboration, and accountability. Responding effectively to this dynamic environment requires a focus on specific leadership activities by senior sales leaders, field sales managers, and salespeople. A sales leadership framework is presented and used to identify and discuss specific leadership challenges and important research questions at different sales organization levels. Several new directions for sales leadership research are proposed to improve sales leadership thought and practice.     

Incentive Salience and Improved Performance

Using data from 441 call center employees at a large North American financial services firm, we studied how the frequency of thinking about an incentive available for performance led to increased output on an important performance metric. We find that people think more frequently about noncash tangible incentives (merchandise and travel) than cash incentives and that as the frequency of thought increases, performance increases. This leads to a larger performance boost for tangible incentives compared to a cash incentive of equal purchasing power. These results show an additional benefit from the use of tangible incentives and help answer the question regarding the psychological processes which make incentives motivating.