By analyzing MRI scans of the foxes, Hecht and her colleagues showed that both the foxes bred to be tame and those bred to be aggressive have larger brains and more gray matter than those of the control group. These findings run contrary to other studies on chickens, sheep, cats, dogs, horses, and other animals that have shown domesticated species have smaller brains, with less gray matter, than their wild forebears.
Note the article and how it is written compared with current day research. Refreshing.