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ch player's strategy is given by a pair (a, a The first component I. Alexander R (1987) The &obey of Moral sntems (Aldine de Cayter, New Toth). 2. Rand DG, Nowak MA (2012) Human cooperation. Trends Cogn Ski 117:413-425. 3. Malls AP, Semmann D (2010) How Is human cooperation different? PAWS Trans A Soc

ial pressure in charitable ghing. 0 ) (con 127(01-56. 24. Cain DM. Dane J. Newman GE 0014) Giving versus giving in. Aced84,W Ann (Mk 505-533. 25. Rand DG, Greene JO, Novak MA (2012) Spontaneous giving and calculated greed. Name 4890416)427-m 26. Nielsen UN. Titan JR. Wengstrarn E 0014) Second thought