Apparently the least intelligent vegetable is the parsnip.
Electrodes were attached to various vegetables, and they plotted the electro-response through the cell-structures of different vegetables.
If the parsnip was a human, its response would have been more like a slow, deep, unconcerned yawn. i.e. it didn't notice anything.
The electro-response stimulated in Brasiccas [inc. cabbages, cauliflowers etc] was very much different, and would have been more like a scream [if readings were translated according to human nerve receptors]
I'll never forget this...one scientist likened the response in a cabbage as 'like a Janis Joplin shriek'.
So...before you call anyone a cabbage these days...think on! It's probably more acurate to call them a Mr Sleepy Parsnip!