[user104658]

Originally Posted by Oliver_W

If the age were to change, it should go up. People's brains aren't fully developed until about 25, so making decisions which can effectively wreck the country should be left to those more suited to thinking it through.

If you want to go down that route - the brain doesn't simply reach a plateau and stay there. It peaks in the 20's and then starts to decline. By age 45 the brain, including reasoning and memory function, is already in decline compared to the late 20's. The average 65 year old has nowhere NEAR the same reasoning function as the average 18 year old.

Shall we start voting at 25 and then stop at 45 maybe?

Then, of course, you have the fact that some people simply never develop effective reasoning abilities or skills at any age. Will we have a test?