Hello Fosh, I am a licensed cosmetologist and I will answer your question...there's an ez test to do but please be careful doing it! Take a few pieces of the hair and put a match to it, yes you heard me right, put a match or lighter to it. If it burns slowly and has an odor to it, it's REAL hair. If it balls up, melts, and has no odor, it's fake. Your animal hairs consist of yak, angora, sheep & horse (mostly used for "fantasy" hair pieces). Also, you should NEVER put a hot iron or flat iron to synthetic hair. It can melt the hair and it's not going to curl in the 1st place. That hairdresser was out of her mind, you can get real hair at "those shops" but you are going to pay a high price for it. That's another way to tell if it's real! LOL
Well miscupid just said test it by burning a piece of it. I believe it too. I bought fake hair and I can't even put a curling iron near it even with hot level 1. My sister bought the ones that says real human hair and she can curl, straight, cramp...whatever she does with it. I would suppose only human hair can do all that. Plus you should be able to tell the difference between human and animal hair... Can't you?
I agree with answer above--if you get real quality human hair for extensions, they will be super expensive. This is especially true if you are getting cuticle human hair - (this is when the hair is cut of a donor's head and all the hair is kept in the same direction). This type of hair is in short supply and expensive.