Intellectual similarity of virtual twin pairs: Developmental trends

Virtual twins (VTs) are same-age unrelated siblings reared together from infancy who replicate twinship, but without the genetic relatedness. A 2005 report from the ongoing Fullerton Virtual Twin Study found an IQ intraclass correlation of .26 (p < .01, n = 113 pairs) and a within-pair difference of 13.22 IQ points. The average age of VTs in that study was 8.10 years (SD = 8.56, range: 4.01-54.84 years). An opportunity to retest members of 43 VT pairs, 1.70-8.96 years after their time 1 assessment, allowed additional analyses of genetic and environmental influences underlying general intellectual development. A decrease in the VT IQ correlation and an increase in the within-pair difference were indicated, consistent with increasing genetic and/or non-shared environmental influences and decreasing shared environmental influence on general intellectual development throughout childhood.     

A treatment trial of an information package to help patients accept new dentures

Intolerance of dentures can be very distressing and difficult to treat. Therefore, 44 patients, having had partial or total dental clearance, completed the Brief Symptom (Psychiatric) Inventory, the Hospital Anxiety and Depression Scale and the Satisfaction with Life Scale. Allocated alternately, each patient had treatment as usual or watched a video containing information, recapitulated in a leaflet, based on the Self Regulatory Model of health beliefs explaining the experiences of wearing dentures and how to tolerate them. They were then fitted with dentures. Two and six weeks later, although both groups expressed favourable expectations of their dentures, the control group deteriorated continually on all measures, correlated with a decline in self-reported dental functioning. The video group improved on all measures except Satisfaction with Life. Therefore, our study is unique in showing that appropriate management of patients can arrest (1) clinically significant distress which can be occasioned by the replacement of teeth by dentures and (2) the development of complaints which may be seen as spurious. Experimental procedures are suggested to determine the influences which have brought this about in our study.     

A reanalysis of the personal/impersonal distinction in moral psychology research

Greene and colleagues [Greene, J., Sommerville, B. R., Nystrom, L. E., Darley, J. M., & Cohen, J. D. (2001). An fMRI investigation of emotional engagement in moral judgment. Science, 293, 2105-2108.] have revealed an apparent distinction in folk psychology between ‘up close and personal’ and ‘impersonal’ moral dilemmas. Reasoning about these types of dilemmas is purportedly supported by partially dissociable neural systems. However, further investigation of the data supporting this hypothesis indicated that only a small number of stimuli used by Greene et al. are driving the effect originally found. Implications of the apparent distinction initially reported and of other research in the domain of moral psychology are discussed.