Why men become nervous while talking to women ?

 Approach Anxiety - The anxiety felt by men when they talk to or approach a girl they like.

This stems from our ancestral past of living in close-knit tribes.

1. Fear of humiliation - If you approached a woman and screwed up, this news will spread like wildfire cause in a tribe of about 150 people everybody knew about everybody else. 1)Men will make fun of you and call you names. 2) Women will know you are not relationship material and will distance themselves from you.

2. Gene survival - If a woman rejects you, she is saying that your genes are not worth carrying forward. 

3. Fear of Death - If the woman you approach is already in relationship with a man. Then,that man will attack you and try to kill you to send a message that no man should approach her if they want to live and also to assert his dominance.