Johansson, G. Frankenhaeuser, M.&Magnusson, D. Catecholamine output in school children as related to performance and adjustment.Scand. J. Psychol.,1973, 14, 20–28.‐Excretion of two catecholamines, adrenaline and noradrenaline, was studied in a group of 240 children, sampled from a longitudinal study, during a “passive” period (viewing a film) and a subsequent “active” period (performing an arithmetic test). In the group of boys the mean adrenaline excretion increased significantly during the active as compared with the passive period. Among the children of both sexes, those who increased their adrenaline output during the arithmetic test as compared with the preceding passive period, performed better on the test in terms of speed and endurance, than did children who did not respond to mental work by adrenaline increase. Significant positive correlations were found between the secretion of both catecholamines and teachers' ratings indicating good social adjustment and emotional stability, as well as with measures of the pupils' subjective satisfaction with their school