An extrovert mathematician will be looking at the other guy's shoes.
Look for Fresh Prince
Because there are already too many targets. (credit: some old veteran bum looking guy sleeping on a bench at the police station I went to today.)
It's are all red and glossy.
Ask them to pronounce 'unionized.'
The extroverted mathematician looks at YOUR shoes when he's speaking to you.
When talking to you, the extrovert mathematician looks at *your* shoes.