wizzard0, why didn't you use the original title, as per HN guidelines? Your title doesn't match what I read from the article at all. Environment is only mentioned once and culture isn't mentioned at all.
UPD: Also... isnt "when Steinberg told the adolescents that their friends were watching from an adjacent room, they took significantly more risks" an environment/culture influence? I don't mean environment like "nature", but the social one, and that includes peer pressure.