Categorical perception of race.

Area of Science:

• Cognitive psychology
• Social psychology
• Neuroscience

Background:

• Categorical perception (CP) traditionally assumes innate or learned divisions of continua.
• Recent research indicates CP can occur with novel stimuli, like unfamiliar faces.
• The role of stimulus categories, beyond individual representations, in causing CP remains unclear.

Purpose of the Study:

• To investigate if stimulus categories, specifically race, enhance CP effects.
• To determine if CP depends on individual stimulus representation or category membership.
• To test if continua between faces of different races exhibit stronger CP than same-race continua.

Main Methods:

• Utilized continua of facial stimuli varying in race.
• Compared CP effects for continua crossing racial boundaries (Black-White) versus those within a single race (Black-Black, White-White).
• Assessed perceptual judgments to quantify CP strength.

Main Results:

• Continua between Black and White faces showed significantly stronger CP effects.
• CP effects were more pronounced for continua between distinctly represented individuals.
• These effects were further amplified when individuals belonged to different racial categories.

Conclusions:

• CP effects are enhanced when continua span categories, such as race.
• Both individual stimulus distinctiveness and category membership contribute to CP.
• Racial categorization plays a significant role in modulating face perception and CP.