If I fits I sits – even in an imaginary square
Cats appear to ‘see’ contours that aren’t there – much like humans fall for optical illusions.
Takeaway
Cats seemed to sit in an illusory square (just four corners) about as often as in a real one.
What the study did
- Cats famously like sitting in boxes – or in squares taped on the floor.
- Owners printed and laid out pairs of shapes: a real square, a Kanizsa square (an illusion made of four ‘Pac-Man’ corners) and a control shape.
- Owners ran the test at home, wore dark sunglasses so they couldn’t cue the cat, and recorded where the cat sat.
- Nine cats sat on a shape: the square 8 times, the illusory square 7 times, the control just once.
The numbers
Show data table
| Group | Value (selections) |
|---|---|
| Real square | 8 |
| Illusory square (Kanizsa) | 7 |
| Control shape | 1 |
Data source: Smith, Chouinard & Byosiere 2021, Appl Anim Behav Sci 240:105338, Results 3.1 'Descriptive data' and Table 2: 16 selections by 9 cats (square 8, Kanizsa 7, Kanizsa control 1).
Show data table
| Group | Value (pairs) |
|---|---|
| Trial 1 | 121 |
| Trial 2 | 53 |
| Trial 3 | 43 |
| Trial 4 | 38 |
| Trial 5 | 34 |
| Trial 6 | 30 |
Data source: Smith, Chouinard & Byosiere 2021, Results 3.1 'Descriptive data' text: 561 enrolments; 121, 53, 43, 38, 34 and 30 pairs completed Trials 1–6.
Limitations
Tiny sample: 561 enrolments but only 30 pairs finished; done at home during COVID and needs a controlled replication.
Citation
Smith GE, Chouinard PA, Byosiere SE (2021). If I fits I sits: A citizen science investigation into illusory contour susceptibility in domestic cats (Felis silvestris catus). Applied Animal Behaviour Science. DOI: 10.1016/j.applanim.2021.105338
For general information only; it does not replace advice from your vet.
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