Answer to Question 1
Nonverbal communication differs widely from culture to culture. Research has found that many of the primarily negative emotions, such as anger or disgust, can be recognized across cultures, but that many of the positive emotions, such as joy and happiness, are communicated with culture-specific signals.
Answer to Question 2
During same-sex conversations, girls and boys learn the rules and assumptions about communication, and these rules follow them through life. As adolescents, they begin to communicate in mixed-sex groups with the rules they learned from same-sex communication, which can cause problems. For example, girls learn to nod their head during conversations with other girls. This lets the talker know that she is being listened to. When a woman nods her head during a conversation with a man, she may simply be showing him that she is listening, but he thinks she agrees with him. When a man doesn't nod his head when a woman is talking to him, she may think he isn't listening to her.
Vocal communication between honeyguides and humans.
microbiological communication
Therapeutic Communication Skills
Essentials of Human Communication (6th Edition)
Art and culture
Sample Size Affects Sampling Error