Final answer:
Facial expressions for Ekman's six basic emotions are determined by biology, as they have been found universal across different cultures and even in congenitally blind individuals.
Step-by-step explanation:
The facial expressions for Paul Ekman's six basic emotions are determined by C. biology. This conclusion is based on Ekman's extensive research which demonstrated that the ability to produce and recognize facial expressions of emotions seems to be universal regardless of cultural background. His research included studies with a man from a preliterate society in New Guinea, which had had no contact with the outside world as well as studies with congenitally blind individuals. Both cases supported the idea that facial expressions associated with emotions such as happiness, surprise, sadness, fright, disgust, contempt, and anger are innate and not determined by nationality, gender, or culture.