Echoing the first book, it amuses me when people are like "eww, I don't want to read a book about how to manipulate people into being friends with me." I'm like...did you read the book, or are you reacting to your strawman of it? The author literally called himself out on being a phony and fake pretentious at one point and how that cost him a valuable relationship. One of the tenets is literally 'become genuinely interested in other people." That's literally the opposite of being fake and manipulating them.

Those who want a more scientific treatise of the topic can pick up Influence by Robert Cialdini, who is a researcher in the psychology of persuasion.