1. Nervous emotions: When men face women they like or admire, their language organization ability often decreases due to nervousness, resulting in a situation where they cannot speak.
2. Lack of confidence: The lack of confidence in one's ability to express oneself, or the worry that one's words will not be accepted by others, makes men become quiet and reserved in front of women.
3. Social anxiety: Some men may have symptoms of social anxiety, which are particularly evident when interacting with the opposite sex, leading to difficulties in normal communication.