A Revisit to Words With/Without Negative Prefixes

I posted about words with/without negative prefixes not too long ago - and about the fact that certain words sound odd without their negative prefixes.

Some readers have added to the list of these odd sounding words:

(in) dividual
(un) couth
(un) kempt
(un) trammelled
(dis) gruntled
(in) effable
(in) ept
(un) requited

Interestingly, trammelled and requited were the only words from this list that spell check accepted without the negative prefix attached.

On a separate note, in the original post I asked for readers' thoughts about a name for this phenomenon. I received these two wonderful responses:

antithesislessness from The Virtual Linguist

a theory of negativity from Freckled Writer

"One way to not be illusioned is to never have been disillusioned."

- Author unknown

Words With/Without Negative Prefixes

I was just thinking about the fact that certain words seem to be used so much more frequently with their negative prefixes than without their negative prefixes (to the point that these words sound funny without their negative prefixes. Consider the following words:

(in)controvertible
(ir)refutable
(in)consequential
(in)effectual
(in)numerable
(in)sipid
(in)dolent
(in)advertent
(in)or(un)conscionable

These are just the first words like this that came to my mind and the majority have the negative "in" prefix. Please add to the list by clicking the comment button below. Also, can anyone think of a name to give this phenomenon?