Technical question - they say people felt 23pc less animosity. Assuming their measurements are okay, what would the statistical power of this experiment ? I dont think they report a null hypothesis.
I had never seen 'pc' used as a short hand for percent (%) until recently in an article (can't remember where), where they used 'pc' repeatedly. Unfortunately the article was also talking about the 'pence' of money, so I found it impossible to figure out from context whether they were talking about a 'pence' or a 'percent'.
In the US, I have seen 'pct' used instead of '%', but not too frequently. I had never seen 'pc' used until recently.
A couple of possibilities:
* For plain-text content that might migrate into a Web page (or emanate from a Web page), the special meaning of '%' in that context might motivate some to avoid the character entirely.
* When typing on a cell phone, one may want to avoid '%' because it often requires shifting to an alternate character set, typing a non-alpha character, then shifting back.
Teletypes didn't start out with a % symblol.
It's a psychology study, a study from a field whose results famously fail to be replicated roughly 2/3 of the time, even when they meet the 0.05 P-factor criterion that assures publication.
Also, many modern psychology studies don't have control groups, and don't consider the null hypothesis. Too much trouble.
Also also, a paywalled study funded by taxpayers. Wasn't this practice supposed to have been stopped?
That's certainly one problem -- many have argued that it's too easy to meet this evidentiary standard, which explains why so many weak, non-replicable psychology papers get published.
You comment comparing psychology to physics is apt -- the evidentiary standard in hard science fields is much higher.