Dale Carnegie created it, Tim Ferriss is a century too late to point as origin.
Dale Carnegie and Steven Covey have both been heavily influenced by Alfred Adler, the Austrian psychotherapist and founder of individual psychology.
https://bsky.app/profile/ifbookspod.bsky.social
It really is all the same book.
For nerds (like me) who think data and statistics are the way to persuade people, you're doing yourself a disservice by ignoring the truth. Lots of people think sales are icky, but much of life is influenced by your ability to persuade and sell, even yourself, to others.
It’s almost like the designation of “self help” is so broad as to be totally useless.