SummaryA sample of 104 British parents with criminal convictions had an average fertility of 3·91 children as compared with 2·21 for the general population. The result suggests that fertility for criminal behaviour is dysgenic involving an increase in the genes underlying criminal behaviour in the population.

SummaryNormative data are reported for intelligence, height and head circumference for a sample of 1553 6- to 15-year-olds in Saudi Arabia, and for the correlations between these variables. Intelligence was tested with the Standard Progressive Matrices, on which the Saudi sample obtained a British IQ of 76.2. There were no significant differences in means between boys and girls and differences in variability were inconsistent. The heights of the Saudi sample were generally lower than those of the American norms. The differences (...) in head circumferences between the Saudi children and the American norms were inconsistent. Correlations between IQ and height were weaker than those found in other studies but correlations between IQ and head circumference were positive. (shrink)

Raven10 years in Mexico. The mean IQs in relation to a British mean of 100 obtained from the 1979 British standardization sample and adjusted for the estimated subsequent increase were: 98·0 for whites, 94·3 for Mestizos and 83·3 for Native Mexican Indians.

The Standard Progressive Matrices test was standardized in Estonia on a representative sample of 4874 schoolchildren aged from 7 to 19 years. When the IQ of Estonian children was expressed in relation to British and Icelandic norms, both demonstrated a similar sigmoid relationship. The youngest Estonian group scored higher than the British and Icelandic norms: after first grade, the score fell below 100 and remained lower until age 12, and after that age it increased above the mean level of these (...) two comparison countries. The difference between the junior school children and the secondary school children may be due to schooling, sampling error or different trajectories of intellectual maturation in different populations. Systematic differences in the growth pattern suggest that the development of intellectual capacities proceeds at different rates and the maturation process can take longer in some populations than in others. (shrink)