Which is NOT a factor that affects teenagers ability to resist peer pressure and stand up for their own values?

A lot of things keep teenagers from standing up to their values. It is in their nature to be affected by it as they are still exploring the world and a lot of hormonal changes in their body make them emotionally vulnerable.

The new found info about the world also makes them sometimes go against their parents, mentally as they think they were not aware of the actual world and were in some fool's paradise as shown by the elders.

They thus develop an exploratory nature and indulge in things they wouldn't normally indulge in.

Moreover, they are in a stage when they want to get accepted by the world and they start with their peer group. Thus they do things which they think will make them more acceptable.