If I'm correct, that Pew research is only looking at the US?
Yesterday someone (a JW) shared on Facebook some sensational article that claimed that archaeologists had found evidence of a huge ancient army whose remains were supposedly found on the seabed of the Red Sea, thus "proving" that the account of the Exodus was accurate. Well, the picture of two divers holding a skull looked familiar, so I got on the case and bingo!, that picture was from another archaeological discovery of 2014, but in a underwater cave in Mexico. So, the news item was an hoax. Then I visited the brazilian website where it had been posted. And looked at the comments section. What I read was UNBELIEVABLE.
Most of the posters were obviously evangelical and pentecostal Christians. They nearly had orgasms with the news. But when someone dared to say the item looked like an hoax, they jumped that poster with such fanatical hate, I can't even describe how ignorant, hate-filled, disgusting, outrageous things were written. I never saw JW's going so low on the ignorance scale like that. If you could read portuguese, I would give you he link, but I hope you believe me. It was among the most ignorant, hateful drivel I have ever seen. All this to say that, at least outside the US, I don't think the JWs are on the bottom of the scale when it comes to common sense ... fundamentalist evangelicals are, for sure.