Retain salience of group categories, have typical group members, have a non-threatening setting, maximum generalisation of positive attitudes to outgroup as a whole
Challenges in intergroup contact field studies: attrition, need to keep participants in the study for "long enough", need to be able to match data across time points
Contact did not work for minority members in the Binder et al. (2009) study, possibly because it did not reduce intergroup anxiety for minority members
In the Swart et al. (2011) study, complex effects work best in the direction from contact to prejudice, e.g. contact increased empathy, which in turn improved attitudes and decreased hostile tendencies
The bystander-calculus model subscribes to the view that emotions are the result of cognitive interpretation, and self-serving needs (not other's needs) are crucial