Movie S1.

The movie illustrates the stimulus generation and task procedure using an example trial. On each trial, a dynamic face movement generator (1) randomly selected a combination of individual face movements called action units (AUs; 21) from a core set of 42 AUs (minimum = 1, maximum = 4, median = 3 AUs selected on each trial). A random movement is assigned to each AU individually using seven randomly selected temporal parameter values – onset latency, acceleration, peak amplitude, peak latency, sustainment, deceleration, and offset latency. In this example trial, four AUs are randomly selected – brow lower (AU4) color-coded in yellow, cheek raiser (AU6) color-coded in blue, nose wrinkler (AU9) color-coded in pink, and lip stretcher (AU20) color-coded in red. The randomly activated AUs are then combined to produce a random facial animation (here, ‘Stimulus trial’). Observers in each culture viewed the resulting facial animation played once for a duration of 2.25 seconds. If the random face movements matched their mental representation of a facial expression of ‘pain’ or ‘orgasm,’ they categorized it accordingly (here, ‘Pain’) and rated its intensity on a 5-point scale from ‘very weak’ to ‘very strong’ (here, ‘Strong’).