RT Article T1 When bystanders increase rather than decrease intentions to help JF Social psychology VO 46 IS 2 SP 116 OP 119 A1 Greitemeyer, Tobias 1969- A2 Mügge, Dirk Oliver LA English YR 2015 UL https://krimdok.uni-tuebingen.de/Record/1630513334 K1 Bystander effect K1 Helping behavior K1 Rationality K1 Diffusion of responsibility