How can it be said that shaming doesn’t work when it influences people’s behavior even if they don’t admit that it does?

Call it what you may, peer pressure, shaming, etc. it has been done for ages and will be used for some time in the foreseeable future. It appears those who are shamed or pressured by society, their family, their homies, school chums, community, etc. will defend to the death they are not changed, directed, steered, etc. by what others think. Even if one doesn’t admit to it, in ways, small and innocuous to bold and ostentatiously they have. In time passed it was smoking, even if you did not care to smoke, you’d be seen as strange if you didn’t smoke because that was the social thing to do. Growing up in the 60s and early 70s if you did not sport long hair (guys) you were seen as weird. Today it might be sagging pants, definitely wearing of bras, or in some ways leaving a big “carbon footprint”, even down to how many times a day one bathes. To some point (maybe small) everyone is shamed into doing something or to avoid something, so why try to allege “It doesn’t happen to me”?