170 9 General Intelligence in the Everyday Human World real-world naive physics need to be? This is a question to which we have no scientific answer at present. Our own working hypothesis is that the analogy does not need to be extremely close, and with this in mind in Chapter 16 we propose a virtual environment BlocksNBeads World that encompasses all the basic conceptual phenomena of real-world naive physics, but does not attempt to emulate their details. Framed in terms of human psychology rather than environment design, the question be- comes: At what level of detail must one model the physical world to understand the ways in which human intelligence has adapted to the physical world?. Our suspicion, which underlies our BlocksNBeadsWorld design, is that it’s approximately enough to have e Newtonian physics, or some close approximation e Matter in multiple phases and forms vaguely similar to the ones we see in the real world: solid, liquid, gas, paste, goo, etc. e Ability to transform some instances of matter from one form to another e Ability to flexibly manipulate matter in various forms with various solid tools e Ability to combine instances of matter into new ones in a fairly rich way: e.g. glue or tie solids togethermix liquids together, etc. e Ability to position instances of matter with respect to each other in a rich way: e.g. put liquid in a solid cavity, cover something with a lid or a piece of fabric, etc. It seems to us that if the above are present in an environment, then an AGI seeking to achieve appropriate goals in that environment will be likely to form an appropriate “human- like physical-world intuition." We doubt that the specifics of the naive physics of different forms of matter are critical to human-like intelligence. But, we suspect that a great amount of unconscious human metaphorical thinking is conditioned on the fact that humans evolved around matter that takes a variety of forms, can be changed from one form to another, and can