How does volumizing/thickening shampoo+conditioner work?

I know it works.... i use it, because my hair is really thin. but how does it work exactly?How does volumizing/thickening shampoo+conditioner work?
Usually, they have a little higher pH level. This will cause just the slightest bit of dryness. When your hair is a little dryer and exposed to a highter pH level, it expands the cuticle %26amp; hairshaft, giving you a little added volume.

ballet