Humans usually have a social norm against flattery. Yes we flatter each other, and often, but we usually flatter indirectly. So just how big of a fig leaf does it take to hide flattery? Consider item #1 from a post on “the seven techniques for ingratiation and influence that are most effective in moving up the corporate ladder without looking like a kiss-ass”:
Frame flattery as likely to make the boss uncomfortable. …one manager whom we interviewed noted that he commonly prefaces flattering remarks with such phrases as “I don’t want to embarrass you but. . . ,” or “I know you won’t want me to say this but. . . ,” or “You’re going to hate me for saying this but.” (more)
Note that this approach makes the praise seem no less glowing, and it offers little reason for observers to less suspect the praise was designed to gain favor. So how could flattery without this addition be unacceptable, yet flattery without this addition be acceptable?
This example suggests that the key social norm is that you should not encourage others to flatter you. While there is a weak norm against praising others to gain their favor, the stronger norm is against your explicitly rewarding others for praising you. So by directly claiming that someone is not encouraging you to praise them, you declare them innocent of violating the key social norm against encouraging flattery from others.
Of course it is hard to see why anyone should take your mere claim that they do not encourage flattery as much evidence for this conclusion. After all, they are still a boss, you could still gain by flattering them, and your claim that they do not encourage flattery is itself additional flattery!
Yet I’ll bet it does work. Which just goes to show that human social norms have a limited scope. We can only manage to express, learn, and enforce a limited number of social norms, while the social behavior that our norms must police are vast and vary widely. As a result, while our norms appear on the surface to discourage flattery, in fact they just move it a level or two away from the norms.
While this does little to actually discourage flattery, or bosses from encouraging flattery, it does greatly reward those who are smart enough to see how to flatter just outside the scope of the usual rules. Hypocritical social norms reward intelligence. Which is why, according to my story, humans have huge brains.