i'll admit up front that i am 'psycho' about this issue-but then i was 'the one' who dealt with the horrendous 'it will never happen' consequences through my career in social services (and saw it happen with my elementary classmates BACK IN THE EARLY 70's).
i have a huge issue with letting kids begin 'dating' (parent sanctioned-not just 'he's my boyfriend' by virtue of playing dodgeball together at recess) in elementary school (and middle school depending on the age).
unless you know what your child/the other child/the social environment they exist in considers 'dating' you may be setting them up for WAY more than you anticipate.
when i was a kid, 7th grade was the time many of the girls set for the absolute LATEST they could get a boyfriend. boyfriends by parental understanding/beliefs were those you held hands with, ate lunch with, met up with at the dance (parents drove separatly). THAT was NOT the social understanding among the kids. boyfriends were the guys that you 'necked' with (even if you did'nt want to-it was expected-you were titled a 'tease' or a 'baby' if you did'nt) such that by the time you hit your freshman year of high school if you were still with them (even if you only hooked up the last few months of 8th grade) you would be consumating your relationship (if you were'nt with the same guy but had 'dated' in jr. high the expectation was that you'de move to that end allot faster-you were 'experienced' or 'broken in'

).
working in social services in the 90's and this decade i encountered WAY TOO MANY pregnant 12 and 13 year olds whose parents were aghast that their dd was pregnant ("how can she be? she's never had her first period-i never told her about the facts of life cuz i was waiting till she got her first period"). well-a girl's first period just means she did'nt get pregnant the first time she ovulated-if she was having sex before that first time then unprotectected the odds are she was going to get pregnant. it was very telling to me-the bulk of the girls i encountered in this situation began 'play dating' (parents taking 9/10 year old girls to a 'kids movie' to sit in a separate row with an 11/12 year old boy-IN THE MIDST OF PUBERTY- 'just holding hands' (well, momma could'nt see what was happening below her line of vision

). the little girls who were holding hand (and other things) at 9/10 did'nt consider it out of line to go a little bit further at 10/11-and all the way by 11/12

the boys were often caving to the peer pressure of their older sibs/friends-the girls were far to immature to reccognize they were WAY to young to be doing what they were doing (and uneducated in sex they believed it when a boy told them they could'nt get pregnant if they had'nt had a period yet-that it was the way a girls 'showed' a guy she loved him, that 'everyone else does it-you're just a baby if you don't').
i am due to have my 30th high school class reunion this year-it is PATHETIC how many of my classmates have listed on the reunion website children who were born to them in EARLY junior high (and i did not grow up in an uneducated/neglected child area which some might point to as a cause-it was a very wealthy area with a population of parents who fearing being labled as 'uncool' by their kid, not only permitting very early 'dating' but encouraging it).
my dd is 14 and dating is a frequent topic. my dh and i have set the guide line for her and her db (just shy of 12) that no dating until highschool and only then if they demonstrate maturity sufficent to make appropriate decisions fully aware of the life long consequences.