What a bullshit argument.
They've been alive longer, that means their brain has also deteriorated
Do you know why people are conservative when they are older?
It's the exact same reason why they are so progressive when they are younger.
They want society to be exactly like they want it to be.
That means that in their youth they have to fight to change it to what they want, and in their old age they have to fight to keep what they have created.
There's also a research that actually shows conservatives have a lower IQ.