This is also a myth. Normally our hair grows about ¼ inch a month, give or take a bit. Some people are luckier and have hair that grows just a little longer in a month. You can give that a boost by eating a lot of protein, maybe sprout ½ inch monthly. But, cutting your hair does not cause it to grow faster.
People with shorter hair do appear to have faster growing hair because the end do not have as many slits or breaks in them, as a person that have longer hairstayles. And shorter hairstyle need to be maitained more with more haircuts to keep that style.
People who use hair dryers and curling irons on their hair daily (or often) do get more breaks and split ends though no matter the length of their hair. The heat causes the hair to become more brittle and does damage the hair. That's why they now have all kinds of styling aides for hair to help combat the problems caused by heat on hair.
So if you use heat to style or dry your hair you might think you hair does not grow fast, or if you have a shorter hair style you might think your hair grows faster. With all that said there is one other thing to be said hair on the same head does not all grow at the same rate. 100 hairs in one patch of the head will not all grow longer at the same time. The only natural way to increase hair growth is by exercise, as the increased blood flow to the scalp increases growth rate.
