If I recall correctly, if the experimental subjects know each other, the chances of action also go up.
You do recall correctly according to the first guy you cited, and Experiment 2 in the paper you cited had 70% of friend pairs and 40% of stranger pairs helping.
You do recall correctly according to the first guy you cited, and Experiment 2 in the paper you cited had 70% of friend pairs and 40% of stranger pairs helping.