Look for Picasso abstract facial features.
You may have to wipe away the drool from their face to properly assess this.
Look them directly in the eye and then glance sideways to see if they have another head.
Not to be mistaken with conjoined twins or a couple with separation anxiety.
Do you have to shake their hand or just hold it?
Could they also mix some paint or a good martini for you?
Check for matching leg lengths.
Some inbreeding mountain people have one leg longer than the other to aid with circumnavigation of mountainous terrain.
Problems answering questions in clear English.
Although this could just mean they work for Fox News and don’t have the teleprompter on.