Without exception, all of studies I've seen purporting it have been terrible. Sometimes with claims made which don't match the actual data. Other time with experimental controls which render it pretty much worthless as anything but suggestion for a better study. The most absurd I remember is a 20 something american on reddit proudly citing a study on a small group of senior citizens in another country to show that it's counterproductive. As if, even if it hadn't been a pretty poor study to begin with, there wouldn't be some pretty big differences in social reactions to things between a 20 and 80 year old in two different countries.