Yes my hair is thicker on the left and thinner on the right. It grows faster on the left side as well. Each time I go in for a cut my hairdresser says it's about 1/2 longer than the right.
I've been reading about hair growth for a while for a while. Here is what I've learned.
Most people are completely unaware of the fact that the individual hairs on your head and body grow independently of one another. Each hair follicle produces hair based on its specific genetic instruction and can be affected by oil build-up and irritants. Itís also possible that the hair follicles will produce hair that is of a different texture than the other hair follicles. The vdifference is usually very slight. If you look closely you can see some differences between individual hairs. The proof of this is most noticeable in the fact that different hair follicles produce differently colored hairs.
If you have hair on one side of the head that appears to grow longer, faster, stronger, or thicker, it may be a matter of normal variance. Or it may be a from external influences. If you favor sleeping on one side or the other, you may be have some erosion of the hair due to rubbing against the pillows or bed linens. If you spend a lot of time driving in your car with the window down and your hair on one side is being blown more by the wind, causing the hair to be roughed up.
My mother swears that she looses alot of hair every year around her birthday. I have yet to look that up.