Endocrine activity in air traffic controllers at work. II. Biological, psychological and work correlates

This is the second in a series of three papers describing cortisol and growth hormone secretion in air traffic controllers at work. Comparing controllers' average hormone levels across a large number of biological, psychological and occupational characteristics yielded few replicable differences. Comparing men with themselves across three repeated endocrine studies showed a consistent but modest relationship between increases in workload and increases in cortisol. For a subgroup of men classified as 'responders', who had significant increases in cortisol parallel with workload, significantly higher scores were found for peer ratings of their work competency, self-reported job satisfaction and their perception of freedom at work provided them by their supervisors. The modest relationships between workload and endocrine secretion were interpreted as evidence for adaptation by the controllers to their working environment. Cortisol responsiveness to large increases in workload was interpreted as reflecting high levels of job investment.