Personnel aptitude test scores as a function of age, education and job type

A battery of personnel aptitude tests were administered and correlated with age for individuals working in skilled and unskilled jobs at a surface coal mining operation. Relationships between age and several measures of cognitive ability were significantly different when computed for skilled versus unskilled employees. Specifically, decreases in cognitive test performance with increasing age were more pronounced for unskilled workers. The partialling out of education had relatively little impact on relationships found between age and cognitive test performance for both skilled and unskilled workers.