Prevalence-induced concept change

The study of Prevalence-induced concept change by David E. Levari as told by Michael Easter in the Huberman Lab Podcast. 

A group of people were asked to look at 800 faces in a row. The participants had to deem whether these faces were threatening or non-threatening. 

At the 200th face, the participants were shown fewer threatening faces. 

For the second study, they had a similar set up but research proposals were used instead. Participants had to deem whether the research proposals were ethical or unethical. 

About midway through, the participants were shown significantly fewer unethical proposals. 

Both studies seem simple. Either the faces were threatening or non-threatening and the research proposals were either ethical or unethical based on a persons' moral grounds. 

However, after the participants were shown fewer threatening faces, they started judging faces that were on the borderline as threatening. Participants said threatening just as many times even though the faces weren't truly threatening.

Similarly, for the study with research proposals, as they get fewer unethical proposals. participants start to deem ethical ones as unethical.

As people experience fewer and fewer problems, we don't actually become more satisfied, we simply lower our threshold for what we consider a problem. So when you apply that to life today, it's like as the world has become a lot more comfortable as we encounter fewer traumas and real problems in our life, we don't necessarily stop and go 'This is amazing!' We simply broaden our definition of what a problem is, of what a discomfort is so we end up with the exact number of problems. - Michael Easter on the Huberman Lab podcast

The solution is volunteering (and I stopped listening there) Will update this post or another as I go along.