Why is AI harder than we think?

"Why AI is harder than we think" - that's the title of a recent paper by Melanie Mitchell at the Santa Fe Institute. The paper is in two parts. The first explores the history of AI, beginning with McCarthy in 1957 to the present. She explains that the AI process has been instead punctuated, and she explains in a way that seems plausible. AI always seems to burst out with dramatic advances, then doesn't live up to the hype, and hibernates for a few years, the so-called AI Winter.