Final answer:
Students rated the computer-generated, sex-neutral faces with angry expressions as unattractive. This is in line with the universality of facial expressions research by Paul Ekman, who found that emotions like anger are recognized and expressed similarly around the world.
Step-by-step explanation:
When researchers showed students a series of computer-generated, sex-neutral faces with expressions ranging from angry to happy, the students consistently rated the angry faces as unattractive. The extensive research by Paul Ekman and others on facial expressions, such as sadness, happiness, disgust, and anger, indicates that our ability to recognize and express these emotions through facial expressions is universal, suggesting a pattern in facial muscle activity that is innate and recognizable across cultures. This reflects a broader understanding in social psychology and evolutionary biology that certain expressions are innately programmed and universally understood, often linked to survival mechanisms. For instance, an angry expression may be perceived as unattractive because it signals a potential threat, which is generally avoided when selecting social partners.