▁Comput ational ▁Model ▁of ▁Self - En for cing ▁Norm s ". ▁American ▁Journal ▁of ▁Soci ology . ▁ 1 1 0 ( 4 ): 1 0 0 9 - 4 0 . ▁ ▁Pat ▁Bar cl ay ▁and ▁Rob b ▁Will er . ▁ 2 0 0 7 . ▁" Part ner ▁Cho ice ▁Cre ates ▁Compet itive ▁Al tr u ism ▁in ▁Hum ans ". ▁Pro ceed ings ▁of ▁the ▁Royal ▁Society ▁of ▁London ▁B : ▁Bi ological ▁Sciences . ▁ 2 7 4 : 7 4 9 - 7 5 3 . ▁ ▁Rob b ▁Will er , ▁Ko ▁K uw ab ara , ▁and ▁Michael ▁W . ▁M acy . ▁ 2 0 0 9 . ▁" The ▁False ▁En for cement ▁of ▁Un pop ular ▁Norm s ". ▁American ▁Journal ▁of ▁Soci ology . ▁ 1 1 5 : 4 5 1 - 9 0 . ▁ ▁Rob b ▁Will er . ▁ 2 0 0 9 . ▁" Groups ▁R ew ard ▁Ind ividual ▁Sac rifice : ▁The ▁Status ▁Solution ▁to ▁the ▁Collect ive ▁Action ▁Problem ". ▁American ▁Soci ological ▁Review . ▁ 7 4 : 2 3 – 4 3 . ▁ ▁Matthew ▁Fe in berg ▁and ▁Rob b ▁Will er . ▁ 2 0 1 1 . ▁" Ap ocal yp se ▁So on ? ▁Dire ▁Mess ages ▁Red uce ▁Bel ief ▁in ▁Global ▁W arm ing ▁by ▁Con trad ict ing ▁Just ▁World ▁Bel ief s ." ▁Psych ological ▁Science . ▁ 2 2