Mason, J. W., Wool, M. S., Wherry, F. E. et al. 1968. Plasma growth hormone response to avoidance in the monkey. Psychosomatic Medicine 30, 760-773.

Several lines of evidence are presented which suggest that psychological response to the venipuncture procedure ['forcibly restrained on rubber mattress in order to perform venipuncture'] may be a major determinant of 'baseline' variability in growth hormone levels. The liability of this system appears to be such that venipuncture effects may occur within the period of a few minutes required for a single venipuncture.