Mav, the original quote you referred to about hearts and brains re liberals and conservative is actually originally as follows:

Not to be a republican at twenty is proof of want of heart;
to be one at thirty is proof of want of head.
-Francois Guisot (1787-1874)

which was later changed by Georges Clemenceau (1841-1929) into:

Not to be a socialist at twenty is proof of want of heart;
to be one at thirty is proof of want of head.

It is interesting how over the years we borrow things and modify them for our own purposes.