14 -16 but a lot of people would disagree
Most teens are really into texting. So they usually get the unlimited texting plan. Teens also use their phones for internet, and calling family or friends.
You can regulate when and how my pre-teens use their cell phones by contacting your cell phone carrier, and asking them to set up parental controls.
adults
The average number is around 90%
There is no recordings of this but I would guess most troubled teens so about 1/4 of our nation has teens that use their phones for bad things.
about 2-3 hours
no
They make them more responsible. (if they pay for it them selves)
yes they did, but they were much bigger than they are now!
are cell phones good influence for teens well if know how to use one
Cell phones can be extremely light these days. Some cell phones can be as light as 40g. Ultimately though, the better the phones usually weigh more so weight is not usually the wisest factor to base a purchase over.
Condoms, ipods, Cell phones, and drugs (only for the fun kids)