[imtringued]

I don't know why people harp on about intelligence. There are plenty stories about ugly ducklings. If you are in the wrong place (geographically, socially) and time your intelligence can mean very little.

If intelligence were some super drug every life form and human would evolve to maximize it. As an extreme example, Koalas evolved to have extremely energy efficient brains that are as small as possible.

Having a powerful "CPU" is worth very little when it is mostly empty and idle most of the time. We send our kids to the program loader (school) for 12 years for a reason. It takes a lot of effort to get the most out of our brains.

People aren't getting dumber. They are getting more isolated and out of touch with the old way of living that was considered the only way 500 years ago. A lot more people are living a lifestyle that used to be associated with aristocracy. More children are being sheltered from the outside world.