Me parece que se refiere a la comparación con un hombre un poco simple o torpe con los monos o primates, que son los animales que más se parecen al ser humano... ¿has visto a un gorila de pie? arrastra los nudillos...

http://www.threeplanes.net/neanderthal.html

Main Entry: Ne·an·der·thal
Pronunciation: nE-'an-d&r-"tol, -"thol; nA-'än-d&r-"täl
Function: adjective
Date: 1861
1 also Ne·an·der·tal /-"tol, -"täl/ : being, relating to, or resembling Neanderthal man
2 : suggesting a caveman in appearance, mentality, or behavior
3 : demonstrating a knuckle-dragging preference of hand tools to power tools for woodworking
- Neanderthal noun


Neanderthal Definition
... 3 : demonstrating a knuckle-dragging preference of hand tools to power tools
for woodworking. - Neanderthal noun.
www.threeplanes.net/neanderthal.html - 2k - 19 Apr 2005 - Cached - Similar pages




Tree Climbers Discussion Group: Re: all you tree climbing knuckle ...
Re: all you tree climbing knuckle dragging hairy monkeys. [email protected].
Tue, 20 Oct 1998 06:04:25 -0500. Messages sorted by: [ date ][ thread ...
www.isa-arbor.com/archives/ isa/treeclimbers/1998/2020.html - 3k - 19 Apr 2005 - Cached - Similar pages

MTWT: DEBUNKING THE MYTH of the Knuckle-Dragging Neanderthal
... the myth all who work in prisons are knuckle-dragging Neanderthals who express
their repressed abused-childhood nightmares upon those in their charge. ...
www.angelfire.com/fl5/mtwt/neanderthal.html - 23k - Cached - Similar pages

Heraldblog: Knuckle-dragging mouth-breather suspended
... Knuckle-dragging mouth-breather suspended. Mark Belling is to the public
airwaves what a turd is to a swimming pool. That a publicly traded company, ...
www.20six.co.uk/Heraldblog/ archive/2004/11/09/1n6gbx1mv5e9i.htm - 32k - Cached - Similar pages

ChavTowns - Saltcoats
... In the course of the rest of the evening, I saw five fights in three bars,
and encountered more knuckle dragging chavs with limited vocabularies. ...
www.chavtowns.co.uk/ modules.php?name=News&file=article&sid=1218 - 76k - Cached - Similar pages

ChavTowns - Skegness
... you knuckle dragging fuckwit ?ha ha ha ha ha ha ha ha ha ha ha etc) and with
the specification unbelievably dumb looking Beyonces, faces like clenched ...
www.chavtowns.co.uk/ modules.php?name=News&file=article&sid=1401 - 77k - 19 Apr 2005 - Cached - Similar pages

otra opción. la referencia a knuckles remite a la idea de alguien primitivo, por eso la imagen de pezuñas por el elemento animal

it does have to do with brain and mindlessness, like the cavemen, and knuckle-dragging refers to BEHAVIOR and HAPPENINGS. I hope this works for you