The Comparative Psychology of Absolute Pitch

Absolute pitch (AP) is the ability to identify, classify, and memorize pitches without an external referent. Musical AP adds the further requirement of pitch naming in the notation of Western music. This chapter considers the more general kind of AP, without the requirement of note naming. It describes several operant experiments in which two species of mammals (humans and rats), three species of songbirds (zebra finches, white-throated sparrows, and black-capped chickadees), and one species of parrot (budgerigars) discriminated and categorized individual tones or ranges of tones related with reward and non-reward. As the discriminations became more difficult, the avian species, which learn their vocalizations, maintained highly accurate AP, but the mammals slipped from lackluster to nonexistent AP. The findings illustrate Charles Darwin's hypothesis that continuity in mental abilities underlies differences among species. The science of comparative psychology owes its first claim to scientific legitimacy to Darwin.