Intelligence, Personality and Brain Rhythms in a Socially Isolated Community

Abstract

SIGNIFICANT correlations between alpha rhythm in the electroencephalogram and ratings of the temperament variable primary-secondary function have been attributed to genetically determined individual differences in a central nervous excitability characteristic^1,2. Since both alpha frequency³and vocabulary score⁴of the Wechsler Adult Intelligence Scale were reported as positively correlated with speed of perception, it seemed possible that performance on the Wechsler Adult Intelligence Scale might be influenced by primary-secondary function. This argument was supported by the finding in 34 subjects of a significant correlation (r= 0.51, P < 0.01) between alpha frequency and total score on the Wechsler Adult Intelligence Scale. Further analysis suggested that the Scale measures non-intellective in addition to intellective aspects of intelligence, and that the former possess a number of electroencephalogram correlates⁵. The fact that previous studies had failed to reveal correlations between alpha rhythm and intelligence was attributed to differences between the Wechsler Adult Intelligence Scale and other intelligence tests, and also to a sampling factor, it being proposed that the emergence of electroencephalogram correlates of non-intellective components of intelligence is dependent on the intellective and socio-economic homogeneity of the sample studied⁵.