Which of the following was an early positivist approach focused on the shape of the skull to explain personal characteristics?

Phrenology is the correct answer because it is an early positivist approach that posited that the shape and contours of the skull could provide insight into an individual's personality, intelligence, and other traits. Phrenologists believed that different areas of the brain corresponded to different mental faculties, and by measuring the bumps and indentations on the skull, they could assess someone's character and abilities. This view stemmed from the belief that physical characteristics could determine behavioral and psychological traits, which aligns with positivist thought that emphasizes empirical evidence and scientific methods.

In contrast, craniometry, while related, specifically focuses on measuring skull dimensions and does not necessarily link these measurements to personal characteristics in the same way phrenology does. Graphology, on the other hand, analyzes handwriting to infer personality traits, and psychoanalysis, developed later, is centered around the study of unconscious processes and does not involve physical measurements of the skull. Thus, phrenology stands out as the approach directly associated with the shape of the skull and the interpretation of personal characteristics, consistent with early positivist principles.