A nationwide survey of a representative sample of U.S. adults was conducted in late 2016, consisting of 402 women and 420 men. The sample was balanced by age and geography. The stimulus array includes 35 purchased stock photos of Wild Animals in a wide variety of natural settings. Carefully selected photos populate a factorial design with seven categories of animals: bears, big cats, birds, reptiles, pachyderms, primates, and a miscellaneous group. Within each category, five types of content are included: portrait, full body, family, bonding, and romance.
A final sample of 822 of online participants viewed each photo for 3 seconds. Webcams recorded facial responses. Affdex FAC analysis generated moment-by-moment emotion metrics (14/sec). Subsequent baseline calibration at the participant level for each photo eliminated order effects.