Tonic Immobility: Differences in Susceptibility of Experimental and Normal Sheep and Goats

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Science  02 Mar 1962:
Vol. 135, Issue 3505, pp. 729-730
DOI: 10.1126/science.135.3505.729


Tonic immobility ("animal hypnosis" or catatonic trance) could not be induced in 1-year-old foster lambs and kids. Control animals, conforming to a characteristic of their species, could be readily immobilized. The suggested explanation for this difference in behavior is that the foster animals did not develop a normal flight distance because of the ambivalent behavior of the "stepmother," who alternately permitted and refused nursing.