Phrenology was a wildly popular but untrue scientific theory.  Find another popular but untrue scientific theory.

URL 1: From Chapter 3: Phrenology was a wildly popular but untrue scientific theory.  Find another popular but untrue scientific theory.
URL 2: From Chapter 4: The Wundtian school and the Wurzburg school had their day in the sun but were mostly forgotten until the artificial intelligence folks came along. For the second URL, explore the link between psych and the AI computer folks.