| Abstract: | Results of 2 experiments with White Leghorn chicks (N = 49) lend support to the hypothesis that tonic immobility is mediated by fear. In Exp. I, Ss injected subcutaneously with adrenalin remained immobile for a significantly greater duration than Ss injected subcutaneously with physiological saline. In Exp. II, it was found that a subcutaneous injection of adrenalin both facilitated the onset and maintained the duration of the immobility reaction in nonsusceptible Ss which previously showed no immobility. An injection of physiological saline neither facilitated nor maintained the immobility reaction in a control group of nonsusceptible Ss. (PsycINFO Database Record (c) 2010 APA, all rights reserved) |
