Longer hair will be easier to spin like mine is and you can yank on the yarn I made, no issue with strength. I will actually spin a skein over time and block it. This insures it holds the twist. I am experienced with different fibers and did not learn from books. My first fleece was 17 lbs of hard work, raw unskirted, a Suffolk sheep that had not been shorn in 3 years. I was able to get a spindle online, and watched a few YouTube videos. Then another experienced gal sent me hers because it was a lot of work, had such fun with it. I do have a unique spinning style and very fast winding method. I want try spinning Nettle fiber next as I just got done with some wood fiber which was cool.
I knew in history they spun hair symbolically or for personal reasons also involving endearment. My brother had me spin his dogs hair into the trim on his slippers last year. Just yesterday I was cleaning out my hairbrush and decided to spin it on my spindle to see what it looks like. Hubby also uses that brush. It did not need carded and I was able to spin more than two feet. It comes out like mohair yarn. I am currently spinning the rest of my Icelandic fleece and it is wonderful stuff. I also loved the mohair which I spun last month. Spinning human hair is really easy. I don't see the difference in what fiber you spin. It isn't creepy, it comes out pretty also. As long as you get the hair from your brush, it's making use of it instead of throwing it away.