Final answer:
The cephalic index is a measurement used to assess the shape of the human skull. Cephalic index change over generations can indicate shifts in the average skull shape within a population.
Step-by-step explanation:
The cephalic index is a measurement used to assess the shape of the human skull. It is calculated by dividing the maximum width of the head by the maximum length and multiplying it by 100. Cephalic index change over generations can indicate shifts in the average skull shape within a population. For example, a decrease in cephalic index over generations may suggest a trend towards a narrower head shape, while an increase may indicate a trend towards a broader head shape.