Behavioral effects of subtotal amygdaloid lesions were investigated to dissociate some of the abnormalities seen after total amygdalectomy. Twelve monkeys [M. mulatta] received bilateral stereotaxic lesions centered in the basolateral amygdala, lateral amygdala, dorsal amygdala or the temporal white matter lying adjacent to the lateral amygdala. The monkeys were compared with others with control operations. The control monkeys than received total amygdaloid lesions (AMX). AMX monkeys exhibited the typical amygdaloid syndrome of hypoemotionality, meat eating, coprophagia and excessive exploration. Monkeys with subtotal amygdaloid lesions would not eat meat or feces, though they were more willing than control monkeys to investigate inanimate objects. Although minor changes in affect were observed, extreme emotional changes seen after total amygdalectomy were found only in the monkey with the largest subtotal lesion. Only hypoemotional animals showed a deficit in learning successive reversals of an object discrimination. This close association suggests that both the hypoemotionality and the successive reversal deficit arise from the same underlying dysfunction.