Example stimuli, trial and study sequence. Stimuli for each of ten situations were created in two subsets (A): the “need-of-help” subset (top) consisted of need-of-help / no-need-of-help picture pairs showing a boy/toddler, a girl, or a bird each in the same situation. The “social context” subset (bottom) included 4 picture categories with varying contexts. Need-of-help pictures are shown on light gray, those showing no-need-of-help on darker gray backgrounds. Note that ratings of one picture per situation were analyzed as part of both subsets, i.e. the child boy “no-need-of-help”/“child-alone” picture. Trial sequence was pseudo randomized and was the same for all 84 pictures (B, see Additional file 1). The study was divided in two halves (C).