No, earliest is age 14 for solo in a glider. They then have to wait until 16 to get a licence under the EU FCL rules. In the UK the first solo age has been 16 until a few months ago but this was changed (by the BGA) to align with and anticipate the implementation of EU rules, which although in place legally are not in effect in practice yet in the UK. Solo at 14 has been the case in Germany for a long time, with no particular adverse consequences afaik. Allowing someone to solo is entirely the discretion of the instructor, as it has always been.
Why the hurry? I ve got nothing against it, but some are petrified at that age and would be much better off waiting until that little bit more mature.
You're mixing up age with maturity. I've flown with 12 year olds (and younger) who have demonstrated incredible maturity, responsibility and capability. I've also flown with 30 year-olds who've demonstrated none of those attributes! As an instructor it's imperative to identify an individual's capability and ability to cope before sending them solo. That's best done through testing, assessment, etc. and not through an arbitrary "ok, off you go..."
The great thing about gliding is that it provides an environment that allows individual's to progress at their own rate. In my experience of UK gliding clubs, there's usually a few pairs of eyes keeping watch over you too :-)
We had our youngest member at the Kestrel Gliding Club RAF Odiham go solo a couple of months ago aged 15, as soon as the rule change and weather allowed. He started flying aged 9, and has had over 300 flights since then. When not flying, he mucks in with the various tasks any other member does. He is also one of the most regular attendees on non-flying days to keep things maintained.
From what I have seen, the best way to make responsible youngsters is to give them responsibility.
I don't think there's any reason that a 14-year-old can't go solo, given a mature outlook and provable skills but I'm not so sure about the whole culture surrounding soloing on the date it becomes legal.
It is highly unlikely, given the random nature of the British weather and availability of instruction and aeroplanes, that the student will reach the point that they would normally be sent solo, exactly on their birthday. Logically, one could say they're either being held back unnecessarily or being sent off too early.
It also attaches a slight air of 'failure' to those who don't make it into the air on their significant date - rubbish of course but I've overheard jokes in the bar and it could give you a bit of a complex if you were sensitive.
I'm not sure about the long-term consequences of a seriously early solo in terms of continuing in the sport - yes, it's the best time to learn and get good habits but I've seen many "solo at 14/16" articles in the local papers (good) but often fail to find these people at the club several years later (bad). Time will tell...