The head shape can be determined at a distance and may give you an indication of the person’s personality. Here are some examples:
A high crown (highest point of the head is at the crown) with a low forehead person has a tendency to be dominating, skeptical and persistent. They have a quick, skeptical mind and insist on being shown facts as the basis of their judgments. They can be determined, persistent, hard to influence and difficult to coerce.
A high forehead, low crown (highest point is at the hair line) person has a tendency to be hopeful, optimistic and trusting but can be discouraged by adversity. They have a willingness to believe in others, are sympathetic and benevolent. They tend to begin projects with high hopes but can become discouraged and give up without accomplishing their goal.
Round head people (widest part is just above the ears) tend to be fearless and a dominating force. They plunge ahead, often throwing caution to the wind.
Square head people (vertical rise above the ears with a flattened top) have a tendency to be cautious, prudent and dependable. They tend to have moderate appetites and passions.
Source: Amazing Face Reading by Mac Fulfer, J.D.