Cautionary Remarks on the Use of Clusterwise Regression

Clusterwise linear regression is a multivariate statistical procedure that attempts to cluster objects with the objective of minimizing the sum of the error sums of squares for the within-cluster regression models. In this article, we show that the minimization of this criterion makes no effort to distinguish the error explained by the within-cluster regression models from the error explained by the clustering process. In some cases, most of the variation in the response variable is explained by clustering the objects, with little additional benefit provided by the within-cluster regression models. Accordingly, there is tremendous potential for overfitting with clusterwise regression, which is demonstrated with numerical examples and simulation experiments. To guard against the misuse of clusterwise regression, we recommend a benchmarking procedure that compares the results for the observed empirical data with those obtained across a set of random permutations of the response measures. We also demonstrate the potential for overfitting via an empirical application related to the prediction of reflective judgment using high school and college performance measures.     

Impact of negative affectively charged stimuli and response style on cognitive-control-related neural activation: An ERP study

The canonical AX-CPT task measures two forms of cognitive control: sustained goal-oriented control (“proactive” control) and transient changes in cognitive control following unexpected events (“reactive” control). We modified this task by adding negative and neutral International Affective Picture System (IAPS) pictures to assess the effects of negative emotion on these two forms of cognitive control. Proactive and reactive control styles were assessed based on measures of behavior and electrophysiology, including the N2 event-related potential component and source space activation (Low Resolution Tomography [LORETA]). We found slower reaction-times and greater DLPFC activation for negative relative to neutral stimuli. Additionally, we found that a proactive style of responding was related to less prefrontal activation (interpreted to reflect increased efficiency of processing) during actively maintained previously cued information and that a reactive style of responding was related to less prefrontal activation (interpreted to reflect increased efficiency of processing) during just-in-time environmentally triggered information. This pattern of results was evident in relatively neutral contexts, but in the face of negative emotion, these associations were not found, suggesting potential response style-by-emotion interaction effects on prefrontal neural activation.     

Satisfaction and Stressors in a Religious Minority: A National Study of Orthodox Jewish Marriage

The paucity of mental health studies with Orthodox Jews makes culturally competent counseling care unlikely. In this large‐scale investigation of marriage among Orthodox Jews, most respondents reported satisfaction with marriage and spouse, although satisfaction was highest among recently married couples. The most significant stressors were finances, communication, physical intimacy/sexuality, time pressures, and in‐law conflicts. Counseling interventions are discussed. La escasez de estudios sobre salud mental en poblaciones de judíos ortodoxos limita la posibilidad de ofrecer un cuidado de consejería culturalmente competente. En esta investigación a gran escala sobre el matrimonio entre judíos ortodoxos, la mayoría de los participantes indicaron satisfacción con su matrimonio y esposo/a, aunque la satisfacción fue mayor entre las parejas recién casadas. Los elementos estresantes más significativos fueron las finanzas, la comunicación, el contacto íntimo/sexualidad, la falta de tiempo, y los conflictos con la familia política. Se discuten intervenciones para la consejería.     

Type D personality predicts poor medication adherence in myocardial infarction patients

Type D personality, the combination of negative affectivity (NA) and social inhibition (SI), is an emerging risk factor in cardiovascular disease. This study aimed to examine one possible behavioural mechanism to explain the link between Type D and ill-health. It was hypothesised that Type D personality would predict medication adherence in myocardial infarction (MI) patients. In a prospective study, 192 MI patients (54 females and 138 males) completed measures of Type D personality and provided demographic and medical information 1 week post-MI, and then 131 patients went on to complete a self-report measure of medication adherence 3 months post-MI. It was found that Type D personality predicts adherence to medication, after controlling for demographic and clinical risk factors. Critically, the constituent components of Type D, NA and SI, interact to predict medication adherence, after controlling for the effects of each component separately. Poor adherence to medication may represent one mechanism to explain why Type D cardiac patients experience poor clinical outcome, in comparison to non-Type D patients. Interventions, which target the self-management of medication, may be useful in these high-risk patients.     

A Broader View of “Self” in Egocentric Social Judgment: Current and Possible Selves

Virtually all previous research addressing the self as a standard of comparison in social judgment defined the self to be one's current-held characteristics. We extended research on egocentric definitions of social categories (Dunning, Perie, & Story, 1991 Dunning, D, Perie, M and Story, AL. 1991. Self-serving prototypes of social categories. Journal of Personality and Social Psychology, 61: 1–12. [Crossref], [Web of Science ®] , [Google Scholar]) and the self-image bias (Lewicki, 1983 Lewicki, P. 1983. Self-image bias in person perception. Journal of Personality and Social Psychology, 45: 384–393. [Crossref], [Web of Science ®] , [Google Scholar]) by measuring a broader definition of “self” which includes possible selves. In two studies, measures of college students' self-systems (current and possible selves together) accounted for three times as much variance in social judgments (M?=?12.9%) than did measures of their current selves alone (M?=?4.2%). We argue for the theoretical and empirical benefits of using a broader definition of self in social judgment research.     

How to Gain Eleven IQ Points in Ten Minutes: Thinking Aloud Improves Raven's Matrices Performance in Older Adults

ABSTRACT

Few studies have examined the impact of age on reactivity to concurrent think-aloud (TA) verbal reports. An initial study with 30 younger and 31 older adults revealed that thinking aloud improves older adult performance on a short form of the Raven's Matrices (Bors & Stokes, 1998 Bors, D. A. and Stokes, T. L. 1998. Raven's Advanced Progressive Matrices: Norms for first-year university students and the development of a short form. Educational and Psychological Measurement, 58: 382–398. [Crossref], [Web of Science ®] , [Google Scholar], Educational and Psychological Measurement, 58, p. 382) but did not affect other tasks. In the replication experiment, 30 older adults (mean age = 73.0) performed the Raven's Matrices and three other tasks to replicate and extend the findings of the initial study. Once again older adults performed significantly better only on the Raven's Matrices while thinking aloud. Performance gains on this task were substantial (d = 0.73 and 0.92 in Experiments 1 and 2, respectively), corresponding to a fluid intelligence increase of nearly one standard deviation.     

Promoting social responsibility amongst health care users: medical tourists’ perspectives on an information sheet regarding ethical concerns in medical tourism

Background

Medical tourists, persons that travel across international borders with the intention to access non-emergency medical care, may not be adequately informed of safety and ethical concerns related to the practice of medical tourism. Researchers indicate that the sources of information frequently used by medical tourists during their decision-making process may be biased and/or lack comprehensive information regarding individual safety and treatment outcomes, as well as potential impacts of the medical tourism industry on third parties. This paper explores the feedback from former Canadian medical tourists regarding the use of an information sheet to address this knowledge gap and raise awareness of the safety and ethical concerns related to medical tourism.

Results

According to feedback provided in interviews with former Canadian medical tourists, the majority of participants responded positively to the information sheet and indicated that this document prompted them to engage in further consideration of these issues. Participants indicated some frustration after reading the information sheet regarding a lack of know-how in terms of learning more about the concerns discussed in the document and changing their decision-making. This frustration was due to participants’ desperation for medical care, a topic which participants frequently discussed regarding ethical concerns related to health care provision.

Conclusions

The overall perceptions of former medical tourists indicate that an information sheet may promote further consideration of ethical concerns of medical tourism. However, given that these interviews were performed with former medical tourists, it remains unknown whether such a document might impact upon the decision-making of prospective medical tourists. Furthermore, participants indicated a need for an additional tool such as a website for continued discussion about these concerns. As such, along with dissemination of the information sheet, future research implications should include the development of a website for ongoing discussion that could contribute to a raised awareness of these concerns and potentially increase social responsibility in the medical tourism industry.

     

Cognitive style and suicidal behaviour: implications for therapeutic intervention, research lacunae and priorities

Cognitive style is a well-established theoretical construct but there is considerable ambiguity in the way it has been used and uncertainty regarding the nature of its role in suicide. There is no evidence that specific cognitive dispositions prime people for suicide but there are indications that suicide is associated with a constriction in cognitive style. This constriction leads to decrements in problem-solving and information processing that can be addressed in therapeutic contexts. To help a suicidal person become a better problem-solver is not a trivial task but the evidence suggests that enriching cognitive styles through the development of thinking skills is possible when the therapy session is construed as a learning collaboration.     

One Family at a Time: A Prevention Program for At‐Risk Parents

The purpose of this study was to examine the effectiveness of a psychoeducational parenting program with at‐risk parents of young children. At‐risk was defined as excessive parental use of verbal and corporal punishment combined with low‐income status. All families were seen for 10 weeks, either individually or in very small groups. Results showed that compared with the control group, parents participating in the program significantly decreased their levels of verbal and corporal punishment, anger, stress, and reported child behavior problems; results were maintained at follow‐up. Implications for counselors are provided.