'personify' would be the antonym of 'anthropomorphize'.

Fishy is confused, Anna! How so?

I think 'personify' gets my vote at present. "He's just anthropomorphizing his car" doesn't exactly roll off the tongue.

But I share Bingley's (and Borderman's?) feeling that there must be a word for attaching human qualities to inanimate objects alone.
If there isn't, perhaps we should invent one!