J. Philippe Rushton

THE ALTRUISTIC PERSONALITY AND THE SELF-REPORT ALTRUISM SCALE*

Summary--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 prosoeial orientation. These data suggest there is a broad-based trait of altruism.

Genetic similarity, human altruism, and group selection

A new theory of attraction and liking based on kin selection suggests that people detect genetic similarity in others in order to give preferential treatment to those who are most similar to themselves. There are many sources of empirical and theoretical support for this view, including (1) the inclusive fitness theory of altruism, (2) kin recognition studies of animals raised apart, (3) assortative mating studies, (4) favoritism in families, (5) selective similarity among friends, and (6) ethnocentrism. Specific tests of the theory show that (1) sexually interacting couples who produce a child are genetically more similar to each other in blood antigens than they are either to sexually interacting couples who fail to produce a child or to randomly paired couples from the same sample; (2) similarity between marriage partners is most marked in the more genetically influenced of sets of anthropometric, cognitive, and personality characteristics; (3) after the death of a child, parental grief intensity is correlated with the childs similarity to the parent; (4) long-term male friendship pairs are more similar to each other in blood antigens than they are to random dyads from the same sample; and (5) similarity among best friends is most marked in the more genetically influenced of sets of attitudinal, personality, and anthropometric characteristics. The mechanisms underlying these findings may constitute a biological substrate of ethnocentrism, enabling group selection to occur.

Differential K theory: The sociobiology of individual and group differences☆

Abstract Differential K Theory is proposed to help systematize individual and group differences in life histories, social behaviour and physiological functioning. K refers to one end of a continuum of reproductive strategies organisms can adopt, characterized by the production of very few offspring with a large investment of energy in each. At the opposite extreme is the r-strategy in which organisms produce a large number of offspring but invest little energy in any one. Between-species comparisons demonstrate that these reproductive strategies correlate with a variety of life history traits including: litter size, birth-spacing, parental care, infant mortality, developmental precocity, life span, intelligence, social organization and altruism. As a species, humans are at the K end of the continuum. Some people, however, are postulated to be more K than others. The more K a person is, the more likely he or she is to come from a smaller sized family, with a greater spacing of births, a lower incidence of DZ twinning, and more intensive parental care. Moreover, he or she will tend to be intelligent, altruistic, law-abiding, behaviourally restrained, maturationally delayed, lower in sex drive and longer lived. Thus diverse organismic characteristics, not otherwise relatable, are presumed to covary along the K dimension. Group differences are also hypothesized, such that, in terms of K: higher socio-economic > lower socio-economic; and Mongoloids > Caucasoids > Negroids.

THIRTY YEARS OF RESEARCH ON RACE DIFFERENCES IN COGNITIVE ABILITY

The culture-only (0% genetic–100% environmental) and the hereditarian (50% genetic–50% environmental) models of the causes of mean Black–White differences in cognitive ability are compared and contrasted across 10 categories of evidence: the worldwide distribution of test scores, g factor of mental ability, heritability, brain size and cognitive ability, transracial adoption, racial admixture, regression, related life-history traits, human origins research, and hypothesized environmental variables. The new evidence reviewed here points to some genetic component in Black–White differences in mean IQ. The implication for public policy is that the discrimination model (i.e., Black–White differences in socially valued outcomes will be equal barring discrimination) must be tempered by a distributional model (i.e., Black–White outcomes reflect underlying group characteristics).

Genetic Similarity Theory: Beyond Kin Selection

We present genetic similarity theory (GST), which incorporates the kin-selection theory of altruism under a more general principle. GST states that a gene ensures its own survival by acting so as to bring about the reproduction ofany organism in which copies of itself are to be found. Rather than behaving altruistically only toward kin, organisms are able to detect other genetically similar organisms and to exhibit favoritism and protective behavior toward these “strangers,” as well as toward their own relatives. In order to pursue this general strategy, an organism must, in effect, be able to detect copies of its genes in other organisms. We order several data sets with this theory including (a) kin recognition studies in animals raised apart, (b) assortative mating, (c) intrafamilial relations, (d) human friendship and altruism, and (e) ethnic nepotism. We discuss a strong and a weak version of GST and offer some predictions for future research.

Teacher Personality Traits and Student Instructional Ratings in Six Types of University Courses.

Colleague ratings of 29 personality traits were studied in relation to student ratings of teaching effectiveness in a sample of 46 psychology teachers. Instructors were evaluated in six different types of university courses, ranging from freshman lecture classes to graduate research seminars. Major findings were as follows: (I) Rated teaching effectiveness varied substantially across different types of courses for a given instructor; (2) teaching effectiveness in each type of course could be predicted with considerable accuracy from colleague ratings of personality; and (3) the specific personality traits contributing to effective teaching differed markedly for different course types. It was concluded that psychology instructors tend to be differentially suited to different types of courses and furthermore that the compatibility of instructors to courses is determined in part by personality characteristics.

RACE DIFFERENCES IN BEHAVIOUR: A REVIEW AND EVOLUTIONARY ANALYSIS

Abstract Racial differences exist on numerous heritable behaviour traits such that Caucasoids fall between Mongoloids and Negroids. Across samples, ages, and time periods, this pattern is observed on estimates made of brain size and intelligence (cranial capacity=1448, 1408, 1334 cm 3. , brain weight=1351, 1336, 1286 g; IQ scores=107, 100, 85); maturation rate (age to walk alone, age of puberty, age of death); personality and temperament (activity level, anxiety, sociability); sexual restraint (gamete production, intercourse frequency, size of genitalia); and social organization (marital stability, mental health, law abidingness). These observations may be explained in part in terms of gene-culture coevolutionarily based r/K reproductive strategies.

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.

Whole brain size and general mental ability: a review.

We review the literature on the relation between whole brain size and general mental ability (GMA) both within and between species. Among humans, in 28 samples using brain imaging techniques, the mean brain size/GMA correlation is 0.40 (N = 1,389; p < 10−10); in 59 samples using external head size measures it is 0.20 (N = 63,405; p < 10−10). In 6 samples using the method of correlated vectors to distill g, the general factor of mental ability, the mean r is 0.63. We also describe the brain size/GMA correlations with age, socioeconomic position, sex, and ancestral population groups, which also provide information about brain–behavior relationships. Finally, we examine brain size and mental ability from an evolutionary and behavior genetic perspective.

Extraversion, neuroticism, psychoticism and self-reported delinquency: Evidence from eight separate samples

Abstract Eight separate samples of high school and university students (Total N = 410) in Britain and Canada were used to test predictions from Eysencks theory that delinquents should be high scorers on scales of extraversion, neuroticism, and psychoticism. Self-report paper- and pencil-questionnaire measures of both personality and delinquency were administered under conditions that ensured anonymity. The evidence showed clear support for a relationship between high delinquency scores and high scores on both extraversion and psychoticism. These relationships held up across diverse samples and different ways of analyzing the data. No support was found for a relationship between delinquency scores and the dimension of neuroticism.