How long? I like any length between [ halfway down her back <> At her waist ] I think it's true for most guys. And long hair is the most feminine these days. At least that's what I think. Some girls can look great with short hair but very few. Find out what looks best on you and if you like your look.
Of course it's true. For the same reason a peacock is less attractive when it's tail feathers are clipped off or a used-to-be-fluffy cat after it's shaved. But for humans it's a bit more complicated than that. It's the total package. For me if you're fat with acne then long hair isn't going to help much. But if you're hot even when bald then long hair will make you hotter. I prefer long drapes and a plush carpet, not bare windows and bare floors.
It depends on what kind of hair you have. There is no point having really long hair and it looks ratty and thin. If you go to a really good hairdresser they can give you a shorter cut that will look really fashionable and often they are better at framing your face than longer styles. It also depends on your fashion choices. If you love bohemian and hippy styles then go with longer hair to suit that personality and if you like more modern and chic fashion maybe you should go with a more modern fashionable and shorter style. Just keep in mind it's much easier to stuff up a short hair cut so go to a really good hairdresser. Regardless of what guys say they will not care whether your hair is short or long as long as it flatters your face shape and personal style.