Problem Solved… Uh oh.

“How do you solve a problem like Maria?” the nuns famously sing in The Sound of Music. The thing is, even if they fixed Maria’s tendency to wander off, habit askew, they still might not be satisfied. That is, based on research coming out of Harvard.

According to Daniel Gilbert, professor of psychology at Harvard, and several of his colleagues, humans have a tendency to redefine problems even if they are being solved. It’s something called prevalence induced concept change, and can alter how we see progress, whether the issue is large or small. “Our studies show that people judge each new instance of a concept in the context of the previous instances,” Gilbert wrote in a paper published in Science. “So as we reduce the prevalence of a problem, such as discrimination for example, we judge each new behavior in the improved context that we have created.”

For example, in one study, participants were shown pictures of threatening faces. Even as the number of threatening faces went down, the participants started to perceive neutral expressions as threatening. Another example: Participants were asked to review studies that might be unethical. As the number of unethical studies was lowered, participants began to view the innocuous studies as unethical.

“Expanding one’s definition of a problem may be seen by some as evidence of political correctness run amuck,” Gilbert wrote. “They will argue that reducing the prevalence of discrimination, for example, will simply cause us to start calling more behaviors discriminatory. Others will see the expansion of concepts as an increase in social sensitivity, as we become aware of problems that we previously failed to recognize.” He notes that his group’s studies take no position on this, but merely point out the phenomenon. “That is what the phrase ‘more research is needed’ was invented for,’” he wrote.