Analogies suggest that compression explains increasing average IQs. Collectively, software engineers improve the efficiency of data compression software. Language encodes (compresses) perceptions, concepts, theories. Coding supplied by language is analogous to coding of algorithms by software. Also, words are reified abstractions: they are things we can manipulate abstractly — juggling them in a brain. All members of society over all generations collectively improve the efficiency of language. Since abstractions encoded by language are more efficient people can more easily juggle more compressed more efficient words representing concepts, and so can solve problems more efficiently. The next analogy is to economics. Societies collectively compress concepts for the anticipated maximum payoff. Hence all processes relating to problem solving, including the lexicon, should over time reflect the same average rate of increase in efficiency. Society channels problem solving resources for the best economic return. Measurements of increases in the size of the English lexicon, increased efficiency in lighting relative to labor cost, increased longevity and other measures seem to reflect the effect compression has on increasing average IQs, in effect the average problem solving rate. Are there are relevant arguments? Are there other ways to measure this effect? I have some articles on arXiv and RG that consider these issues.