Reflexivity in pigeons.
Pigeons can learn to match symbols to themselves after combined symbolic and identity matching training.
01Research in Context
What this study did
Researchers worked with four pigeons in a lab.
They first taught the birds to match shapes to colors using a symbolic matching game.
Then they added identity matching, where each bird had to pick the same shape it just saw.
Finally, they tested if the birds would match a shape to itself without any training.
What they found
The pigeons chose the matching shape more often than not.
This showed reflexivity - the birds matched new pairs they had never been taught.
It looked like they formed simple equivalence classes, linking symbols to themselves.
How this fits with other research
Bell (1999) found the same pattern in a chimpanzee using similar training.
Both studies show stimulus equivalence works across species.
Palya (1985) taught pigeons to name objects with pecks, proving birds can learn symbolic tasks.
Together, these papers show non-humans can build simple language-like systems.
Why it matters
This gives you a clear model for teaching self-matching skills.
Use symbolic matching plus identity training when teaching learners to recognize themselves in mirrors or photos.
Start with clear A-B relations, then add A-A identity trials before testing for untrained self-recognition.
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02At a glance
03Original abstract
A recent theory of pigeons' equivalence-class formation (Urcuioli, 2008) predicts that reflexivity, an untrained ability to match a stimulus to itself, should be observed after training on two "mirror-image" symbolic successive matching tasks plus identity successive matching using some of the symbolic matching stimuli. One group of pigeons was trained in this fashion; a second group was trained similarly but with successive oddity (rather than identity). Subsequently, comparison-response rates on novel matching versus mismatching sequences with the remaining symbolic matching stimuli were measured on nonreinforced probe trials. Higher rates were observed on matching than on mismatching probes in the former group. The opposite effect--higher rates on mismatching than matching probes--was mostly absent in the latter group, despite being predicted by the theory. Nevertheless, the ostensible reflexivity effect observed in former group may be the first time this phenomenon has been demonstrated in any animal.
Journal of the experimental analysis of behavior, 2010 · doi:10.1901/jeab.2010.94-267