Purple hair.

They vote Republican.

You know that kind of goes out the window with mental illness it doesn't have much to do without how you raised them.
But, sometimes adults do what they want no matter how you raised them.
I raised my kids to be polite, to obey the law, respect people ,and they did chores...
But adult choices and mental illness stripped much of that away

They are very "scammy", they take unfair advantage.

Like people who take food from food banks who don't really need it...

Lack of basic manners or regard for others typically. Sure some adopt these behaviors regardless of their nurturing but generally it's something they were allowed to do and never corrected in early in life or learned watching someone else do it.

Abusing others and then coming up with excuses or "qualifiers" to dismiss their wrong doings.

Lack of accountability.

Anger issues- someone could have gotten them help and instead chose to ignore or allow it.

Being socially inept without having any sort of mental disorder -often means they were ignored or raised by a screen. Etc

they give bad vibes. For example one guy gave me a ride home. While he was drinking and driviving.

They treat people in customer service like crap