Crude historical depictions of African Americans as ape-like may have disappeared from mainstream U.S. culture, but research presented in a new paper by psychologists at Stanford, Pennsylvania State University and the University of California-Berkeley reveals that many Americans subconsciously associate blacks with apes.

The research took place over six years at Stanford and Penn State under Eberhardt's supervision. It involved mostly white male undergraduates. In a series of studies that subliminally flashed black or white male faces on a screen for a fraction of a second to "prime" the students, researchers found subjects could identify blurry ape drawings much faster after they were primed with black faces than with white faces.

The researchers consistently discovered a black-ape association even if the young adults said they knew nothing about its historical connotations. The connection was made only with African American faces; the paper's third study failed to find an ape association with other non-white groups, such as Asians. Despite such race-specific findings, the researchers stressed that dehumanization and animal imagery have been used for centuries to justify violence against many oppressed groups.