Final answer:
Donna's refusal to eat ice cream from a plate because she expects it in a bowl is an example of functional fixedness, a cognitive bias that limits seeing objects beyond their conventional use.
Step-by-step explanation:
Donna's refusal to eat more ice cream off a plate simply because she is fixated on the idea of having a "big bowl" of ice cream is an example of functional fixedness. This is a type of cognitive bias where an individual is so set in their conventional mode of thinking that they fail to see other uses or methods - in Donna's case, not recognizing that the plate can be a viable alternative to a bowl for consuming ice cream, despite offering a larger portion.
Functional fixedness is often described in the context of problem-solving, where individuals struggle to use objects for anything other than their traditional purposes. Duncker's experiment with the candle, matches, and box of thumbtacks illustrates how people need to overcome this cognitive bias to think creatively and solve problems. Similarly, during the Apollo 13 mission, engineers had to overcome functional fixedness to fashion a makeshift air filter to save the astronauts.