Teen Dating
I am raising two of my nieces. One just turned 14, the other 16. It is the 16 year old who started dating, for real, recently. She was actaully fifteen when she asked if she could go out with this boy. I told her we would discuss it and get back with her. My husband would rather die than let her start dating EVER.
But reality check...she is growing up and coming into her own right now.
I have a degree in psychology, which did help in my decision. However, I feel that a teen is ready to date if he/she have been responsible in other areas of their lives. For instance, my niece is an honor roll student, she has always done her chores when asked (not saying she didn't balk sometimes about it, but she does them) and she is and always has been pretty independent. She has had to be because of her earlier years living with her needy parents. As soon as she could she found a job. So in her situation, after discussing the sex, drugs, making good choices when choosing friends, I let her seriously date at fifteen and a half. Seriously meaning going out to movies, the mall together, amusement parks, etc. without an adult following her around.
Of course since niether of them could drive, most of their activites were fairly supervised. She just got her license and this has changed now, but so far she has kept to the rules, most of the time any way, so we are giving her more space. She knows if she messes up, the space will close. So I guess to answer your question, if your kid is responsible in the important areas of his or her life, and she has never given you any major reason not to trust her, 15 or so is reasonable. If she starts letting her grades drop, or starts displaying signs of slipping, then the dating halts until you feel she or he is ready again.