My friend and I had a vivid discussion about politics. We discussed about a system in which people had to go through some sort of intelligence evaluation system. According to their intelligence level they would get a certain amount of votes (higher score means more votes). Most current systems give a moron and a genius both one vote. The issue in that is that the moron votes whoever he likes and doesn't understand the magnitude of what he does. The system of votes according to intelligence would reduce the risk that such a decision has an impact. I am aware that not all people with low intelligence make bad decisions and that not all intelligent people make good decisions, but I think that on average, the more intelligent a person is, the better he understands what consequences his decisions have, and the more likely he is to make good decisions.

One downside I can think of is that the people who make these intelligent tests have to be genuine and make the tests contain many more fields than traditional IQ tests, such as general knowledge and morality (which could be hard to find common ground on).

Another thing many people would probably categorize as downside is, that people can learn these tests. One positive effect of that is that those people who learn for these tests inevitably learn, which could increase the "average intelligence level" of the population. I don't believe that the few "evil" people who study for the tests would tip the scales. Another thing that could make this harder is to make those test have totally random questions, so someone who would intend to "learn it all" would need to learn everything there is to know.

Now that I rambled on to make my point clear, are there any governments who implemented something like that? Have there been discussions on such a system? What could be the downsides of it (other than those already mentioned)?

Here are some related questions that did not answer mine:

Voting according to education (my question does not care about education)

Using IQ tests (IQ tests are largely based on logic, little on general knowledge and not about social behavior / morality, while the test I'm talking about would incorporate those)

edit: The reason for this system would be similar to why most countries restrict voting to adults.

edit2: I don't know if people don't see that I linked to the IQ question and want to close it as duplicate of that or that I didn't explain the difference well enough, so here a bit more in-depth explanation: IQ tests test mostly for logical thinking, math, pattern finding, conclusion making and so on. The kind of test I am proposing would cover many more topics such as general knowledge (a la "Who is often called 'father of evolution'?"), morality (although, thanks to everybody who has replied, I realize that this point would be very hard to do) and anything else that could possibly included.