Destination and source memory in Huntington's disease

Destination memory refers to the recall of the destination of previously relayed information, and source memory refers to the recollection of the origin of received information. We compared both memory systems in Huntington's disease (HD) participants. For this, HD participants and healthy adults had to put 12 items in a black or a white box (destination task), and to extract another 12 items from a blue or a red box (source task). Afterwards, they had to decide in which box each item had previously been deposited (destination memory), and from which box each item had previously been extracted (source memory). HD participants showed poorer source as well as destination recall performance than healthy adults in the proposed tasks. Correlation analysis showed that destination recall was significantly correlated with episodic recall in HD participants. Destination memory impairment in HD participants seems to be considerably influenced by their episodic memory performance.     

Performance on Raven's Matrices by African and White University Students in South Africa

Untimed Raven's Standard Progressive Matrices (SPM) were administered to 309 17- to 23-year-old students at the University of the Witwatersrand and the Rand Afrikaans University in Johannesburg, South Africa (173 Africans, 136 Whites; 205 women, 104 men). African students solved an average of 44 of the 60 problems whereas White students solved an average of 54 of the problems (p<.001). By the standards of the 1993 US normative sample, the African university students scored at the 14th percentile and the White university students scored at the 61st percentile (IQ equivalents of 84 and 104, respectively). The African–White differences were found to be greater on those items of the SPM with the highest item–total correlations, indicating a difference in g, or the general factor of intelligence. A small sex difference favoring males was found in both the African and the White samples, but unrelated to g.     

Psychological essentialism and the differential attribution of uniquely human emotions to ingroups and outgroups

According to the psychological essentialism perspective, people tend to explain differences between groups by attributing them different essences. Given a pervasive ethnocentrism, this tendency implies that the human essence will be restricted to the ingroup whereas outgroups will receive a lesser degree of humanity. Therefore, it is argued that people attribute more uniquely human characteristics to the ingroup than to the outgroup. The present article focuses on secondary emotions that constitute such characteristics. Study 1 showed that members of high‐ and low‐status groups attribute more positive secondary emotions to the ingroup than to the outgroup. Study 2 verified that the differential attribution extended also to negative secondary emotions. No exemplars of emotions were provided in Study 3. Instead, participants had to estimate the means of two distributions of numbers that supposedly represented characteristics of the ingroup and of the outgroup. The results of this third experiment illustrated the reluctance to attribute secondary emotions to the outgroup. The findings are discussed from the perspective of psychological essentialism. Copyright © 2001 John Wiley & Sons, Ltd.     

Differential K theory and race differences in E and N

Differential K Theory was recently proposed relating personality to reproductive strategy (Rushton, 1985). The more K the person is (the symbol derives from population biology), the more he or she will delay reproductive effort, produce fewer children and more intensely care for them. Concomitant characteristics include intelligence, altruism, law-abidingness and behavioural restraint. Race differences are hypothesized such that, in terms of K, Mongoloids > Caucasoids > Negroids. Barratt and Eysenck (1984) recently published standardized Extraversion (E), Neuroticism (N), Psychoticism (P) and Social Desirability (L) scores for males and females from 25 different countries, but did not analyse the data in such a way that racial differences were found. In the current study Barratt and Eysenck's data are aggregated across sex and over countries to examine whether theoretical predictions regarding race differences in behavioural restraint do in fact occur. Behavioural restraint was indexed by low E and high N scores. The means for 8 Mongoloid samples (N = 4044) were contrasted with those of 38 Caucasoid (N = 19, 807) and 4 Negroid ones (N = 1906), and the resultant comparisons confirmed expectations. Mongoloids are lower on E and higher on N than Caucasoids, who in turn are lower in E and higher on N than Negroids.     

Race differences in sexual behavior: Testing an evolutionary hypothesis

Population differences exist in personality and sexual behavior such that, in terms of restraint, Orientals > whites > blacks. This ordering is predicted from an evolutionary theory of r/K reproductive strategies in which a tradeoff occurs between gamete production and parental care. Literature is reviewed on differences between the three groups in rate of ovulation, intercourse frequencies, sexual attitudes, developmental precocity, size of genitalia, secondary sexual characteristics, and biologic control of behavior that accord with this formulation. Novel analyses of data from the Institute for Sex Research are also carried out, indicating that American blacks, compared to American whites, are more precocious and less restrained. Their parents were younger when they were born, had more children, and had an earlier mortality. Blacks left home earlier, experienced a variety of premarital, marital, and extramarital sexual events earlier, had a greater number of premarital and extramarital partners, had a greater frequency of marital intercourse, used fewer contraceptives, and had a greater incidence of pregnancy, at a faster rate. The men had larger penises, at a different angle of erection, and maintained intromission longer, while the women had shorter menstrual cycles, more periodicity of sexual response, and a greater number of orgasms per act of coitus. Whites varied their sexual activity more, both with spouses and with prostitutes, although blacks consorted with prostitutes more frequently. Finally, blacks had a shorter duration of marriage and more permissive sexual attitudes.     

Young infants'' sensitivity to movement information specifying social causality

Adults and 3- to 6-month-old infants were tested for their visual preference for two different dynamic displays presented simultaneously on two side-by-side computer monitors. Each display consisted of a pair of colored discs moving either independently (the independent display) or in systematic interaction (the “chase” display), never actually contacting one another. Except for the relative spatio-temporal dependence of the discs' movements, all dynamic parameters on the two displays were controlled and maintained equal. Analysis of looking behavior showed that adults as well as infants looked differentially at the displays. Patterns of preference depended on age. For the infants who completed the experiment, there was a significant transition from more looking at the chase to more looking at the independent display as a function of age. Adults as well as the older, attentive infants, showed enhanced visual attention to the independent display. These results provide first evidence of young infants' sensitivity to movement information specifying social causality for adult observers.     

Brain size and cognitive ability: Correlations with age,sex, social class,and race

Using data from magnetic resonance imaging (MRI), autopsy, endocranial measurements, and other techniques, we show that (1) brain size is correlated with cognitive ability about .44 using MRI; (2) brain size varies by age, sex, social class, and race; and (3) cognitive ability varies by age, sex, social class, and race. Brain size and cognitive ability show a curvilinear relation with age, increasing to young adulthood and then decreasing; increasing from women to men; increasing with socioeconomic status; and increasing from Africans to Europeans to Asians. Although only further research can determine if such correlations represent cause and effect, it is clear that the direction of the brain-size/cognitive-ability relationships described by Paul Broca (1824–1880), Francis Galton (1822–1911), and other nineteenth-century visionaries is true, and that the null hypothesis of no relation, strongly advocated over the last half century, is false.     

The altruistic personality and the self-report altruism scale

This paper is divided into two parts. In the first, the rank order stability of individual differences in altruism across situations is examined and it is found that substantial consistency occurs when due regard is given to the principle of aggregation. In the second, a self-report altruism scale, on which respondents rate the frequency with which they have engaged in some 20 specific behaviors, is found to predict such criteria as peer-ratings of altruism, completing an organ-donor card, and paper-and-pencil measures of prosocial orientation. These data suggest there is a broad-based trait of altruism.