able ▁in ▁this ▁context . ▁One ▁reason ▁for ▁this ▁is ▁that ▁social ▁pressure ▁functions ▁well ▁in ▁small ▁group ▁sizes ▁of ▁ 5 0 ▁to ▁ 1 5 0 ▁individuals ▁( common ▁to ▁nom adic ▁h unter – g ather er ▁pe op les ) ▁but ▁not ▁in ▁communities ▁number ing ▁in ▁the ▁millions , ▁as ▁we ▁see ▁today . ▁Another ▁reason ▁is ▁that ▁individual ▁rec y cling ▁does ▁not ▁take ▁place ▁in ▁the ▁public ▁view . ▁ ▁Following ▁the ▁increasing ▁popular ity ▁of ▁rec y cling ▁collection ▁being ▁sent ▁to ▁the ▁same ▁land fill s ▁as ▁tr ash , ▁some ▁people ▁kept ▁on ▁putting ▁rec y cl ables ▁on ▁the ▁rec y cl ables ▁bin . ▁In ▁Baltimore , ▁the ▁government ▁kept ▁collect ing ▁glass ▁separately ▁for ▁seven ▁years ▁even ▁though ▁it ▁did ▁not ▁rec ycle ▁it . ▁ ▁Rec y cling ▁in ▁art ▁▁ ▁Art ▁objects ▁are ▁more ▁and ▁more ▁often ▁made ▁from ▁rec yc led ▁material . ▁ ▁In ▁a ▁study ▁done ▁by ▁social ▁psych ologist ▁Sh awn ▁Burn , ▁it ▁was ▁found ▁that ▁personal ▁contact ▁with ▁individuals ▁within ▁a ▁neighborhood ▁is ▁the ▁most ▁effective ▁way ▁to ▁increase ▁rec y cling ▁within ▁a ▁community . ▁In ▁his ▁study , ▁he ▁had ▁ 1 0 ▁block ▁leaders ▁talk ▁to ▁their ▁neighb ors ▁and ▁persu ade ▁them ▁to ▁rec ycle . ▁A ▁comparison ▁group ▁was ▁sent ▁f liers ▁prom oting ▁rec y cling . ▁It ▁was ▁found ▁that ▁the ▁neighb ors ▁that ▁were ▁personally ▁contact ed ▁by ▁their ▁block ▁leaders ▁rec yc led