@Robin

But unless you use an actual human brain for your AI, you're still just creating a model that works in some way "like" a human brain. To know that it will work, you'll need to know which behaviors of the brain are important to your model and which are not (voltages? chemical transfers? tiny quantum events?). You'll also need to know what capabilities the initial brain model you construct will need vs. those it can learn along the way. I don't see how you get the answers to those questions without figuring out what intelligence really is unless generating your models is extraordinarily cheap.

For the planes/birds analogy, it's the same as the idea that feathers are really not all that useful for flight as such. But without some understanding of aerodynamics, there's no reason not to waste a lot of time on them for your bird flight emulator, while possibly never getting your wing shape really right.