What's more damaging?

[lindseyann]

I would think the heat. Especially if done frequently.

[martyna_22]

I voted heat styling. It's horrible and there's no denying that.

[lapushka]

Sulfates don't "damage". I think this poll is way off, sorry. I use sulfates on a regular basis, have almost TBL hair and there's no white dot, nor a split in sight. I also use a blow dryer (diffuser) (on warm). There are a lot of myths circulating this place, it appears.

[MINAKO]

Sulfates don't "damage". I think this poll is way off, sorry. I use sulfates on a regular basis, have almost TBL hair and there's no white dot, nor a split in sight. I also use a blow dryer (diffuser) (on warm). There are a lot of myths circulating this place, it appears.

I agree lapushka, but both can cause dryness which is an excellent way for mechanical damage to start from and in most cases it is mechanical damage that wrecks the hair in the end. Or it's deeply penetrating chemicals.
Persnally i don't get the heat thing either, because the way i use it, it's more beneficial than harmful to my hair, it's all about the pros and cons i would say, taking the result we like to achieve into consideration.
Aside from bleaching or relaxing i can do the my hair whatever i want once in a while an it wil be perfectly fine, but all the time in between i tell myself "don't effing touch it!" or as little as possible, high quality tools > gentle detangling > basic bun > silk pillow case > golden!

[fiðrildi]

I would say frequent heat styling as well. It doesn't matter how much nourishment you give to your hair, if you're gonna "kill it" by heatstyling it.