9, 10, 11, 12, 13, 14 is too young to be dating.
Why? Because you're not mature enough. I think the world has enough pregnant 12 and 13 year olds, thank you. Hell, I would even say that most high school students aren't mature enough to really date, but, at least in high school you are more mature than a little sevvie. Also, dating in high school is what gets you prepared for real life because that's what you're going to be thrust into before you know it.