Yep. Id adds to tensile strength. I guess that kind of equates to ‘stiffness’ but it is really a different this. It may be “stiffer” along it’s length but is it the same density, hardness, etc… Stable and tough…
My technical terms may be slightly jumbled but I know what I mean! 
Ahhh you got me wrong, not saying that timber is better, just saying it looks better.
2 out of 5 of mine are polymer.
Timber looks a lot better than polymer.
Horses for courses…
Different materials are better for different applications. I don’t want a light weight target rifle but I’d go a carbon composite stock and carbon wrapped barrel on a gun I was planning to climb mountains with.
