IN the monkey, bilateral amygdalectomy results in a number of behavioural changes which have been well documented1–4. These changes consist of (1) reduction in aggressiveness and relative tameness toward man; (2) increased orality, coprophagia and the mouthing of inedible objects; (3) hypermetamorphosis; and (4) hypersexuality. While these changes may be enhanced by extending the lesion to include the temporal neocortex and hippocampus, it has been established that these behavioural alterations can be produced by ablation of the amygdaloid nuclei alone2.