Cross-sectional studies of personality in a national sample: 1. Development and validation of survey measures

Short scales were developed to measure three broad dimensions of personality in the National Health and Nutrition Examination Survey (NHANES I) Epidemiologic Followup Study. Items to measure neuroticism were selected rationally from the General Well-Being Schedule, and items to measure extraversion and openness to experience were selected by multiple regression from the NEO Personality Inventory. In a sample of 654 men and women from the Augmented Baltimore Longitudinal Study of Aging, all three short scales showed clear evidence of convergent and discriminant validity against full scales in self-reports, and against peer and spouse ratings. Because they were developed and validated on a sample with a comparable age range, the NHANES scales should be useful in examining age trends in these three personality dimensions in a national sample.     

Genetic and Environmental Effects on Openness to Experience, Agreeableness, and Conscientiousness: An Adoption/Twin Study

ABSTRACT Previous research has indicated that extraversion and neuroticism are substantially affected both by genotype and environment. This study assesses genetic and environmental influences on the other three components of the five-factor model of personality: Openness to Experience, Agreeableness, and Conscientiousness. An abbreviated version of the NEO Personality Inventory (NEO-PI) was administered to 82 pairs of identical twins and 171 pairs of fraternal twins reared apart and 132 pairs of identical twins and 167 pairs of fraternal twins reared together. Estimates of genetic and environmental effects for Openness and Conscientiousness were similar to those found in other studies of personality: Genetic influence was substantial and there was little evidence of shared rearing environment. Results for Agreeableness were different: Genetic influence accounted for only 12% of the variance and shared rearing environment accounted for 21% of the variance. Few significant gender or age differences for genetic and environmental parameters were found in model-fitting analyses.     

Modifications of the Poggendorff effect as a function of random dot textures between the verticals

In the present research, we investigated the modification of the strength of the Poggendortf illusion as a function of different densities ofrandom dot textures failing the space between the verticals. The results ofExperiment 1 show that the illusory effect is a nonlinear function ofthe texture parameterr, the ratio of black pixels to white and black pixels, with a minimum forr=0.5, approximately, and a maximum forr=0 andr=1. The results may be interpreted by an analytical model of perceptual space dynamics, in which the effect dependson the amount of interaction between points of different light intensity. A computer simulation performed by applying the analytical model to different values ofr shows a good agreement between the predictions and the experimental data. To test the hypothesis underlying the model, a second experiment was carried out to measure the magnitude of the expansion ofthe space between the verticals as a function of the parameterr. The results are consistent with the hypothesis of the model. The overall data are discussed in terms of their implications on various theories proposed for the Poggeadorff illusion.     

Reading Rates and Digit Span in Bilinguals: The Superiority of Mother Tongue

Several studies have shown a negative linear relationship between speech rate and memory span. This relationship has implications for bilingual studies, as span could be larger in a bilingual's secondary language provided that pronunciation rate is faster than in the mother language. The purpose of this study was to investigate the effects of digit word length on digit span in bilinguals. Experiment 1 tested the effects of digit syllable length on speech rate in five different bilingual groups. Results revealed that digit-reading rates were significantly faster in all mother languages. Experiment 2 examined more closely the correspondence between speech rate and digit span with Portuguese-English bilinguals. Results showed that digit-reading rates were faster and digit span larger in the mother language even if the mean number of syllables per digit was higher. The superiority of mother tongue was discussed according to the view that digits are subject to massive practice in one's native language with a strong tendency to be abbreviated, thus reducing its spoken duration.     

Effectiveness of taping and bracing in balance

Taping and bracing are thought to be effective methods in restricting the ankle's joint motion and assisting prevention of injuries. Research evidence suggests that taping and bracing enhance both the mechanical support and the proprioception of the ankle. However, there is little research concerning the influence of taping and bracing on sport performance. Research has mainly examined tasks with demands on the frontal plane. Therefore, the present study examined the effect of taping and bracing on the performance of a task with demands on the frontal plane. A sample of 30 physical education students (Mage=21.9 yr.) performed a balance task requiring estimation of balance and both right and left deviations. The subjects performed the balance task on four different conditions, with tape, with Swede-O (a lace-up, boot style stabilizer), with Aircast (an inflatable cast), and without any stabilizer. There were no significant differences among the conditions. These findings indicate that taping and bracing do not have negative effects on balance in the frontal plane. This study created concerns regarding the appropriate stabilizer for different tasks, bilateral coordination after the application of a stabilizer, and the influence of psychological factors on prevention of injury.     

Social isolation stress-induced aggression in mice: a model to study the pharmacology of neurosteroidogenesis

Long-term social isolation of laboratory animals is a model to study the behavioral and neurochemical consequences of the absence of social interaction in rodents. Many of the symptoms induced by isolation resemble depression and anxiety disorder symptomatology. Our studies have revealed that male mice socially isolated for more than 4 weeks, exhibit increased aggressiveness, a reduced responsiveness to GABA(A) receptor acting drugs, and a downregulation of brain levels of 3alpha,5alpha-tetrahydroprogesterone (allopregnanolone: 3alpha,5alpha-THP), a neurosteroid endowed with potent positive allosteric modulatory activity of the action of GABA at various GABA(A) receptor subtypes. This downregulation of 3alpha,5alpha-THP appeared to be associated with the reduction of brain type I 5alpha-reductase mRNA and protein expression. Systemic administration of the selective serotonin reuptake inhibitor fluoxetine and its metabolite norfluoxetine normalized brain 3alpha,5alpha-THP content and reduced responsiveness to GABA(A) mimetic drugs in a stereospecific manner. These drugs in nanomolar doses also reduced social isolation-induced aggressiveness with the same stereospecificity as detected in their action on 3alpha,5alpha-THP brain content, while their ex vivo inhibition of serotonin reuptake occurred at high micromolar doses and lacked stereospecificity. From these results we infer that the brain 3alpha,5alpha-THP content physiologically upregulates GABA(A) receptor responsiveness to GABA and that social isolation induces a reduction of brain 3alpha,5alpha-THP content that is probably causally related to the onset of aggression.     

Personality profiles and the prediction of categorical personality disorders

Personality disorders (PDs) are usually construed as psychiatric categories characterized by a unique configuration of traits and behaviors. To generate clinical hypotheses from normal personality trait scores, profile agreement statistics can be calculated using a prototypical personality profile for each PD. Multimethod data from 1,909 psychiatric patients in the People's Republic of China were used to examine the accuracy of such hypotheses in the Interpretive Report of the Revised NEO Personality Inventory. Profile agreement indices from both self-reports and spouse ratings were significantly related to PD symptom scores derived from questionnaires and clinical interviews. However, accuracy of diagnostic classification was only modest to moderate, probably because PDs are not discrete categorical entities. Together with other literature, these data suggest that the current categorical system should be replaced by a more comprehensive system of personality traits and personality-related problems.