There are many, many studies concerning the differences in liberals and conservatives, WRT to their brains.
Most people who are unfamiliar with brain function will (depending on the study and their own prejudices) jump to unwarranted conclusions about them.
No surprise there. And it's not a purely recent phenomenon:
Although it is not true that all conservatives are stupid people, it is true that most stupid people are conservative.
John Stuart Mill
This is true, but it doesn't actually tell you much about conservatives. Most of the studies are like that.
I love the story of "The Three Little Pigs", two of whom were stupid, layabouts and one of whom who was industrious and utilized his time, talent and money judiciously.
The two layabouts, in the story, were food for the Big Bad Wolf. And the industrious brother lived snugly and safely in his little brick house.
Of course now, the two layabouts are coddled and nurtured by the taxpayers time talent and money which is fast destroying the middle class in America.
And then,
There is the Little Hen that asked her neighbors for help in planting, weeding and maintaining her garden. They wouldn't even help her at harvest time. After she gathered in the bounty of her garden winter came.
Then,
her neighbors came knocking on her door looking for handouts. She stated "Where were you when I asked for help? Now, I only have enough to feed my own children".
Of course now, it is a given that the workers owe handouts to those who do not work.
Strange world we live in.