Actually, it wasn't only grunting he investigated, but various other non-verbal sounds people use to communicate, too.
The study is called Growls Laughs and Sobs are better than words at Conveying Emotion, and the result of the study is pretty much as promised in the title.
Apparently people take notice of non-verbal vocalisations more quickly than they do words: of the three emotions studied, which were anger, happiness and sorrow, people noticed happiness most quickly, though anger stayed in the mind for longest.
How did Dr Pell and his colleagues do the study? Well, they employed everything from brain scanners to the delicious and deliberately nonsensical phrase He placktered the tozz.
According to Dr Pell, emotional vocalisations are recognised by a particularly long-evolved part of the brain. This turns out to makes recognition quicker (we've got it down to just one tenth of a second).
This is certainly fascinating, but it's also proof of something I think we really knew. I mean, when the car in front suddenly starts reversing towards us our immediate impulse isn't to say to the driver oh look, darling, I think that car's about to smash into us, is it?
It's really more of an arrrrgggghhh!
Thing To Notice Yourself Using Today: a non-verbal vocalisation. I wonder how many we make for every word spoken?