At first glance, the obvious solution seems to be to create intelligence the same way nature did: some sort of evolution. Some sort of algorithm where multiple "networks" mutate and reproduce in some way, in response to some fitness function. Mutations that make a network more fit result in an increased reproductive rate, while other mutations decrease that rate.

Evolutionary algorithms have been around for a while but haven't really taken off. Maybe the problem is that you can't get from zero to intelligence with a single fitness function.

Think about it: the "fitness function" for our single-called ancestors was not how well they could thrive in a post-industrial service economy. Nor was it how well they could thrive as hunter-gatherers in the African Savannah. It was a very, very different fitness function.

To get from zero to humans, nature had to evolve single-called organisms, then mitochondria, then basic multi-celled organisms, then animals that lived in the ocean, then amphibious ones, then land-dwelling ones, then mammals, then apes, then early humans, then modern humans.

By the way, I left out the overwhelming majority of the steps.

At each step, the evolutionary pressures on these organisms were wildly different. Each set of pressures was necessary in order for the next layer of complexity to evolve.

I think that if we want to evolve an intelligent entity, we would probably have to do it like this.