Political correctness requires mental energy because it forces us to second-guess and inhibit our responses. The human brain has limitations in information-processing capacity so being tired or mentally taxed makes people less politically correct.
Thus, if political correctness is a good thing then we should find that interactions are less productive when people are worn out. However, the opposite turns out to be true.
In one study, mentally exhausted people were found to be less inhibited during a conversation with someone of a different race, enjoyed the interaction 25% more, were rated as significantly less prejudiced, and were 76% more likely to candidly discuss diversity and how to handle this sensitive issue.
Another study asked participants to videotape advice for an overweight teenage girl. People with lower cognitive abilities were more open, more likely to discuss her weight, and were rated by two doctors as giving significantly more helpful advice.
Yesterday we discussed how happiness can sometimes be a bad thing. Similarly, research has found that politeness is detrimental to performance in high-stakes situations like flying a plane or treating a patient in the emergency room.
So, believe it or not, science suggests we should all be a bit more like Donald Trump.