Final answer:
Franz Joseph Gall claimed that the shape of a person's brain, as reflected by the skull shape, could predict their criminality, through the pseudoscientific practice of phrenology.
Step-by-step explanation:
According to Franz Joseph Gall, the shape of the brain (or more specifically, the skull) can be used to predict criminality. Gall was the founder of phrenology, a practice that involved measuring the areas of a person's skull to infer personality traits, character, and mental faculties. This early attempt to link physical characteristics with behavioral tendencies suggested that bumps on the skull reflected underlying brain areas and associated psychological attributes. However, phrenology has been discredited as it lacks empirical support and is considered a pseudoscience.