Hast thou seen Sinnott’s experiment with scary masks and zoo animals? This study makes tell of it:
“Perception of Scary Halloween Masks by Zoo Animals and Humans,” Joan M. Sinnott [pictured here], H. Anton Speaker, Laura A. Powell, and Kelly W. Mosteller, International Journal of Comparative Psychology, 25 (2012): 83-96. (Thanks to investigator Neil Martin for bringing this to our attention.) The authors, at the University of South Alabama, explain:
Zoo animals were tested to see if they perceived the scary nature of Halloween masks, using a procedure that measured the avoidance response latency to take food from a masked human experimenter. Human perception of the masks was also assessed using a rating scale, with results showing that a Bill Clinton mask was rated not scary, while a Vampire mask was rated very scary. Animal results showed that primate latencies correlated significantly with the human ratings, while non-primate latencies did not….
The stimuli were primarily thirteen Halloween masks (Figure 1, panels 1-13) with eyeholes that allowed the masked experimenter to clearly look at the test animal. In addition, a human wearing no mask was used as a control stimulus for zoo animals only (E2, see below, Figure 1, panel 14).
1. Bill: a relatively normal human face, with a small grin showing a few teeth.
2. Al: a relatively normal human face, with a big grin showing lots of teeth.
3. Joe: an ugly human face, with frowning eyebrows and a down-turned mouth.
4. Mike: a normal but completely expressionless white human face, with disheveled hair.
5. Gorilla: a normal black gorilla face, with a grinning mouth showing a few teeth, and disheveled hair.
6. Scream: a white human skull, with glaring eyes, a cut-off nose, and a wide open mouth showing no teeth.
7. Quiltman: an abnormal brown human face, with patches of face material in strange patterns, resulting in several eyes, ears, noses and mouths.
8. Sewage: a skull-like whitish-green scaly human face, with frowning eyebrows, a cutoff nose, and a wide open mouth showing teeth.
9. Hair: a green ape-human face, with a grinning mouth showing teeth, and a lot of hair.
10. Martian: an olive-green skull-like human face, with glaring eyes, a cut-off nose, a grinning mouth showing teeth, and an expanded brain case.
11. Big-Mouth-Closed (BMC): a greenish reptile-like scaly face, with frowning eyebrows, pointed ears, and a closed mouth showing large canines.
12. Big-Mouth-Open (BMO): a brownish reptile-like scaly face, with frowning eyebrows, and a wide open mouth showing large canines.
13. Vampire: a grayish human-like face, with frowning eyebrows, an open mouth with very large canines.
14. The control face of E2 (see below): a normal human face with a slight smile.
At the very end of the paper, the authors seem to suggest replicating the study on kinds of animals, including trained dolphins.