False
The study was over clipping rats wiskers and triming their hair in between wild and domesticated rats. The study is On the Phenomenon of Sudden Death in Animals and Man.
Study
Study
Using electric clippers, the whiskers and hair of the facial area were trimmed before the animals were placed in water at 95 ° F., a temperature at which most intact, control rats swim 60 to 80 hours.
(This is to say without the trimming rats swam 60-80 hours)
Domesticated rats
The first rat swam around excitedly on the surface for a very short time, then dove to the bottom, where it began to swim around nosing its way along the glass wall. Without coming to the surface a single time, it died 2 minutes after entering the tank. Two more of the twelve domesticated rats tested died in much the same way; however, the remaining 9 swam 40 to 60 hours.
That is to say, of the domesticated rats three quickly died and 9 swam for 40-60 hours (control was 60-80 hours wo/ trimmed facial hair).
Hybrid rats
Five of 6 hybrid rats, crosses between wild and domesticated rats, similarly treated, died in a very brief time.
Wild Rats
We then tested 34 clipped wild rats, all recently trapped. These animals are characteristically fierce, aggressive, and suspicious; they are constantly on the alert for any avenue of escape and react very strongly to any form of restraint in captivity. All 34 died in 1-15 minutes after immersion in the jars.
That is to say, wilds rats die in 1-15 minutes because they panic.
Conclusion and potential confusion
The conclusion from the paper, is this
From the results we concluded that trimming the rats' whiskers, destroying possibly their most important means of contact with the outside world, seemed disturbing enough, especially to wild rats, to cause their deaths.
The confusion probably comes from this,
At present it appears that of all these factors, two are the most important: [the restraint involved in holding the wild rats, thus suddenly and finally abolishing all hope of escape; and the confinement in the glass jar, further eliminating all chance of escape and at the same time threatening them with immediate drowning.
"Eliminating hope of escape and chance of escape" isn't exactly scientific wording. Who knows how a rat conceives hope, and how they assess chance; but, they were never given any notion of hope because no rats were rescued and re-experimented. Each trial was done with new rats. So all rats were equally without hope and chance of escape. The only variable was the rats genetics (wild or domestic). The group that swam longer did NOT do so because they were taught they'd be rescued and swam longer with hope (expectation) of rescue. They swam longer because they were domesticated rats and NOT wild rats.