Neither would we suggest that they are particularly stupid.

He looked vexed, as though Willie had said something particularly stupid.

"Coin and stamp collectors," he explained, as though to a particularly stupid child.

She is possessed by a particularly stupid sort of evil.

He had a very quick temper and I suppose he thought me particularly stupid.

I asked him why and he looked at me as though I were being particularly stupid.

By the way, "they have the actual download" is particularly stupid.

But it might also be that we are neither particularly stupid nor particularly backward.

They had not gotten this far by being particularly stupid.

Of course, he'd have to be particularly stupid for that to happen.