Evidence that psychology, like biology, is conserved between human and nonhuman species augurs a shake-up for science and society
In addition to and underlying these changes in theory, Goodall’s data contradicted inferential conventions. Chimpanzee violence suggested that ethologists could infer the origins of chimp behavior from what they understood about human violence—something hitherto dismissed as being contrary to scientific standards.
Historically, science has admitted inference from animals to humans but not the reverse. As historians Lorraine Daston of the Max Planck Institute for the History of Science in Berlin and Gregg Mitman of the University of Wisconsin–Madison, recently noted,
Ethologists who study animal behavior, including that of primates, with close phylogenetic links to humans, have long made it a principle not to infer humanlike mental states from humanlike behavior and until [recently] many scientists in the field frowned upon any discussion of animal mental states.
Perhaps because scientists have been trained to shun such conclusions, examples of human-to-animal inference have been scarce in the scientific literature. This is one of the reasons that chimpanzee homicide, laughing mice and empathetic sheep are considered newsworthy: They represent deviations from normative models—or rather they used to. Now erstwhile behavioral isolates make up the empirical bricks in the foundations of psychobiology, and the limits on what we can infer about humans and animals have changed. Human-to-animal and animal-to-human inferences are legitimately symmetric. A deeper understanding of brain biology has strengthened this sense of equity.