Final answer:
Investigators generally agree that certain facial expressions universally indicate the same emotions, such as happiness, surprise, sadness, fear, disgust, contempt, and anger, introducing a biological basis to emotional expression.
Step-by-step explanation:
Most investigators agree that facial expressions indicate the same emotions in all people. Research by Paul Ekman and numerous studies on emotional expression have shown that there are seven universal emotions associated with distinct facial expressions: happiness, surprise, sadness, fear, disgust, contempt, and anger. Despite cultural differences in emotional display rules, the capacity to produce and recognize these facial expressions is intrinsic and evident even in congenitally blind individuals, pointing to a biological basis for emotional expression. Tone of voice and body language complement facial expressions, signaling emotional states across different cultures.