Final answer:
Your friend's purchased ceramic item is associated with phrenology, a discredited pseudoscience that attempted to link skull features with personality traits.
Step-by-step explanation:
This early 19th-century practice involved measuring areas of the skull to infer personality traits, character, and mental abilities. Credited to Franz Gall, phrenology asserts that the various bumps on the skull reflect the brain regions underneath and their respective functions. Although phrenology was discredited as a pseudoscience due to a lack of empirical support, it did contribute to the early understanding of different brain regions being responsible for different functions.