Being 16 does not necessarily mean you are intellectually incapable of understanding the various political arguments. Hardly an objective observation of yours though, was it, 3T? I think it an incorrect observation, personally. What does tend to change with increasing age is the tendency to accumulate wealth and material items, coupled with greater use of the filter of vested self-interest when reading about matters political.
What I do wonder is whether at age 16 they have sufficient life experience and emotional development to be considered competent to cast a vote.
But the laws surrounding legal majority in this country are blurred anyway, as they are in many countries. At 16, you are technically able to have sex and marry and have children, but not legally able to buy alcohol or cigarettes or drive.
Judging by your OP and YMBs reponse, you both would be perfectly happy with lowering the voting age if you thought that all 16 year olds were true blue tory rather than this notion of yours that they are all budding Che Guevaras, which comes over as being a little hypocritical, don't you think?