162 9 General Intelligence in the Everyday Human World 9.2 Some Broad Properties of the Everyday World That Help Structure Intelligence The properties of the everyday world that help structure intelligence are diverse and span multiple levels of abstraction. Most of this chapter will focus on fairly concrete patterns of this nature, such as are involved in inter-agent communication and naive physics; however, it’s also worth noting the potential importance of more abstract patterns distinguishing the everyday world from arbitrary mathematical environments. The propensity to search for hierarchical patterns is one huge potential example of an ab- stract everyday-world property. We strongly suspect the reason that searching for hierarchical patterns works so well, in so many everyday-world contexts, lies in the particular structure of the everyday world — it’s not something that would be true across all possible environments (even if one weights the space of possible environments in some clever way, say using program- length according to some standard computational model). However, this sort of assertion is of course highly “philosophical,” and becomes complex to formulate and defend convincingly given the current state of science and mathematics. Going one step further, we recall from Chapter 3 a structure called the “dual network”, which consists of superposed hierarchical and heterarchical networks: basically a hierarchy in which the distance between two nodes in the hierarchy is correlated with the distance between the nodes in some metric space. Another high level property of the everyday world may be that dual network structures are prevalent. This would imply that minds biased to represent the world in terms of dual network structure are likely to be intelligent with respect to the everyday world. In a different direction, the extreme commonality of symmetry groups in the (everyday and otherwise) physical world is another example: they occur so often that m