In 1977, a hair sample was taken from 26 newborn babies and their mothers and analysed for lead and cadmium. Six years later, each of these 26 children was given a psychometric test (McCarthy Scales of Children's Abilities). Statistical analysis shows a significant negative relationship between the degree of in utero exposure to cadmium and lead and the child's motor and perceptual abilities. Any effect on memory or verbal skills was not statistically significant. Allowing for the confounding variables does not consistently affect these results.