Color preference in pigeons: stimulus intensity and reinforcement contingency effects in the avoidance of blue stimuli.
Equal brightness across colors keeps preference data clean—pigeons and, by extension, kids may reject blue only when it is dimmer or has a history of free reinforcement.
01Research in Context
What this study did
Researchers tested pigeons on three keys: red, green, and blue. The birds had to peck the key that paid off with food.
First, the lights were set at normal brightness. Then the team matched the brightness of all three colors. Finally, they gave free food while the blue key was lit.
What they found
When brightness differed, the birds rarely pecked blue. Once brightness was equal, blue was picked as often as red or green.
Later, when food came for free during blue, the birds again avoided blue. Brightness alone did not rule choice; the way food was delivered also mattered.
How this fits with other research
Pence et al. (2019) saw blue light covers raise stereotypy in students with autism. The pigeon data show blue itself is not bad; brightness and history matter.
Shvarts et al. (2020) used color cues to cut resurgence in kids and pigeons. Like Joyce et al. (1988), they show color controls behavior only when paired with clear reinforcement.
Siegel et al. (1986) found pigeons learn faster after watching a peer. Taken together, these studies say: check the full context—brightness, model, and payoff—before labeling a color "bad."
Why it matters
Before you call a picture card, room light, or toy "non-preferred," equalize brightness and review how it has been reinforced. A quick brightness match during stimulus preference assessments can stop you from tossing useful items or colors.
Want CEUs on This Topic?
The ABA Clubhouse has 60+ free CEUs — live every Wednesday. Ethics, supervision & clinical topics.
Join Free →Use a light meter or phone app to match the brightness of all color cards before your next preference assessment.
02At a glance
03Original abstract
In a procedure intended to determine color preference in pigeons (which partially replicated Catania, Owens, & von Lossberg, 1983), two keys were illuminated by different colors drawn from a set of amber, red, green, or blue stimuli; this was followed by the presentation of grain when either of the two colors was pecked. The grain was illuminated alternately across trials with the colors presented on the keys. In Experiment 1 the intensity of the color stimuli used was not equalized, whereas in Experiment 2 the intensity of the colors was equalized. The low preference for blue found in Experiment 1, as measured by differential key pecking, was not found in Experiment 2. The discriminability of the intensity-equalized colors was confirmed in Experiment 2a, in which equal-intensity color discrimination problems were presented. In Experiment 3, as in Catania et al. (1983), a response-independent reinforcement schedule was used, but with intensity-equalized colors. In contrast to Experiment 2, very low preference for blue was found here and in Experiment 4, which used a within-subject procedure. These findings suggest that pigeon color preference may be a function of intensity, but all controlling variables have not as yet been identified.
Journal of the experimental analysis of behavior, 1988 · doi:10.1901/jeab.1988.49-265