Transfer of self-control in black (Eulemur macaco) and brown (Eulemur fulvus) lemurs:: Choice of a less preferred food item under a reverse-reward contingency

When presented a choice between two food-type arrays of equivalent size under a reverse-reward contingency, black (Eulemur macaco) and brown (Eulemur fulvus) lemurs transposed their self-control abilities, acquired in a previous experiment, to significantly select the less-desired food item in order to gain access to the more desired one. However, when presented with the choice between two different food-type arrays in which the amount of the less desired food array was larger than the more desired one, large individual differences were revealed: Some subjects established a consistent rule favoring quality or quantity, whereas others exhibited various point of trade-off. These results show that lemurs seem to manage the task considering not only food quantity but also food quality.