We've just updated the title from ‘A lot of teen risk-taking is environment/culture influence, not just “age”’ to part of the subtitle, which hopefully represents well the article without the “Sex and drugs...” bait.
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.