Well, that's something different from the use of "usted" to show respect and courtesy to others.
A higher economic rank does not free anyone from being respectful (at least not for a Mexican). And there's of course a "usted" that can be used to detach from people doing services for others, no matter if they're older or younger, which can be as disrespectful as "tú", depending on the intonation it's been given.
For Spanish learners: trust the good manners you were taught at home. Whenever you've learnt to say "sir/ma'am" or when addressing people with their titles (Mr., Dr., Professor, General...), use "usted" and you'll be fine.
