Additivity of independent and heterogeneous features of a stimulus situation in their effects upon behaviour. For example, the herring gull (Larus argentatus) recognizes its eggs by various features, including size, shape, background colour, and speckling. These features have been shown to be additive in their effects upon retrieval of eggs that have rolled out of the nest. Heterogeneous summation is not a universal law of visual recognition, but it has been shown to hold in a number of cases.
Subjects: Zoology and Animal Sciences.