You do not want to be intelligent. Not in a world where approximately 95% of people are quite stupid. Being intelligent in a democracy of idiots will make your life a hell.
You need to be average dumb, just like the rest of them. It will be much easier for your nerves on a daily basis. You will "naturally" have more social interactions, because you can and because you fit. You won't get aggravated every time you read the news or talk to the administration. It will be much more relaxing. You will not wonder about this or that (i.e. basically everything), loading your brain with questions you will never get answers to, raising your doubts and your chronical stress. Your life will be a blue sky with very few clouds.
95% of people won't think you're arrogant just because you dare to show you have ideas. If you live in France, you will even be able to ask questions to doctors without being thrown out for crime de lèse-majesté.
95% of people won't be envious and try to push you down because you might make things better which is not to their own interest... So you will be able to get a job in a company and even keep it for a while.
Trust me. If you aim at a zen existence, average dumb is what you need. If you're not blessed with it, you will have to fake it. Lifetime extra work and risky risk... Better go for it at birth. Choose carefully your parents. You don't want two total idiots of course, but you don't want clever people either (IQ over 110 to be avoided at all costs). You could think one of each would do the trick, but birds rarely f*ck mice, so that's not a likely solution. Just go for average, as always.
Average is the key to many things in life.
Average dumb, that's what you want. It will be your best asset in life. Comfort guaranteed.
Think about it.