Guest post by Jonah Berger (@j1berger), Professor at University of Pennsylvania’s Wharton School and author of Contagious: Why Things Catch On. This essay is based on his new book Invisible Influence: The Hidden Factors that Shape Behavior Who wouldn’t want to be a bit more influential?  Whether trying to nail that big interview, convince a client, or get the neighbor to finally trim their hedges, most people would love to be a bit more persuasive.  So how do we do that? Imagine you’re stuck…