Hmm, the "articulate" is a better signifier for intelligence or education than the "smartly dressed" part.
Academics for example aren't known for their smart dress sense.
It's not an unreasonable question though. We all make assumptions based on externals.
I know a very lovely lady. Very well dressed. I know she was privately educated.
She's a SAHM now but did hold a professional role previously.
I've known her for years through our DC. I just kind of assumed she was intelligent.
I had occasion to spend far more time than usual with her (long train journey) and our conversation veered off from our usual topics of children, families etc.
I was quite horrified and embarrassed to realise that she couldn't keep up with the conversation between the group. She's not stupid, and as I say she's extremely lovely but she wasn't managing at all, she wasn't following the argument let alone able to contribute to it.
I gently moved the discussion to less difficult ground but spent a couple of days being retrospectively embarrassed that I hadn't noticed earlier.
Completely my own fault, I made assumptions based on her externals not on anything she'd ever said to me.
I'm desperately hoping I haven't been inadvertently rude for the last 5 years. She still seems to like me so hopefully not.