An international team of researchers from Germany, the United States, and the United Kingdom has performed a series of experiments to investigate the role of flexibility and inhibition in problem solving and how they relate to each other in the great-tailed grackle – a behaviorally flexible urban bird species. By assessing the cognitive abilities of these birds using multiple tests, the researchers found that self-control (a form of inhibition) was linked to flexibility, or the ability to change preferences when circumstances change.
The scientists discovered that grackles who were faster to reverse a color preference were also faster to inhibit their behavior in a “go no-go” test, where they needed to touch one shape but not another on a touchscreen computer to get a reward. This behavior suggests that inhibition is involved in learning how to change preferences.
“The grackles are likely inhibiting themselves from choosing the previously rewarded option so they can instead choose the other option, which is now the only option that has food in it,” explained study lead author Corina Logan, a senior researcher at the Max Plank Institute for Evolutionary Anthropology.
However, another measure of flexibility – the time it takes to switch to trying to solve a new option on a puzzlebox after previously succeeding on a different option – correlated negatively with the capacity for inhibition in a “go no-go” test: grackles who were faster to switch to a new option were slower in inhibiting their behavior.
The scientists believe that different birds might use different inhibitory strategies, with those less inclined to inhibit being more open to explore a variety of options. This would help them solve the puzzlebox, but would be less useful in situations when they need to stick to one option, such as those assessed through the “go no-go” test.
Strangely, grackles who did better on a different inhibition test previously thought to measure self-control too, the “detour” test (where the birds needed to walk around to the side of a clear plastic tube to get food from the tube’s opening rather than trying to get it immediately through the plastic), did not necessarily perform better at the “go no-go” test. According to the researchers, while the latter measures self-control (the ability to withhold a response towards something present and wait for something that comes later), the former measures a different, simpler trait: motor inhibition, or the ability to stop a movement that is not useful.
“Our results show that different tests, which are widely referred to as tests of self-control actually assess different cognitive abilities,” says co-author Claudia Wascher, an associate professor of Behavioral Ecology at Anglia Ruskin University.
Further research is needed to assess to what degree can grackles use causal cognition in order to change their behavior in relation to changing circumstances. Better understanding how flexible species react to a changing environment can help inform conservation management plans and facilitate learning how to promote flexibility in animal species that are struggling to adapt to our rapidly changing world.
The study is published in the journal Animal Behavior and Cognition.