Comparative psychology, a new perspective for the 21st century: up the spiral staircase.

This article responds to the continuing obituaries for Comparative Psychology. We understand the field to be a general psychology, a way of understanding the origins of all behavior of all species. We outline a methodological and conceptual foundation for comparative psychology to enter the new millennium-with an anagenetic and dynamic systems perspective. We see an important role to be played by comparative psychologists in managing resources, increasing our activity in social and political issues, and transcending our traditional role as the study of animal behavior to one that makes significant contributions to psychology and humanity by studying relationships between animals and changing environments, and by providing a historical perspective on human evolution.