Is hair density equal throughout the scalp?

Ive noticed that the hair on the back of my head is slightly thicker than the rest, at first I thought this was balding but I recently saw a picture of me when I was 11 and it looks like the hair on the back of my head is thicker than the hair on the top, is it possible that my hair has always been different densites on different parts of the scalp, or is that not possible?

Yes and no. Each person has a particular average donor density, but often on the sides above the ear, the density is lower. When a person starts balding, hair densities will fall in varying areas of the head, so to command this process I do a HAIRCHECK test ( https://baldingblog.com/haircheck-test-how-it-is-done-video/ ) to help me put measurements to hair bulk in different parts of the head, often not seen with my eyes but the men who come to me somehow know that this is happening. This test either confirms or denies their suspicions.