Mason, J. W., Mougey, E. H. 1972. Thyroid (plasma BEI) response to chair restraint in the monkey. Psychosomatic Medicine 34, 441-448.

Study of 14 of these monkeys throughout a longer period of 8 weeks of chair restraint indicated that ... mean BEI [butanol extractable iodine] levels remained significantly elevated through the third week. ... Acute emotional arousal [enforced restraint] elicits stimulation of the pituitary-thyroid system in the rhesus monkey.