The male shrugging emoji, used the same way to express 'I don't know' or indifference with gender specified. Trivia: like facepalm, the shrug emoji's design was directly modeled after the ASCII shrug's posture, making it one of the rare emoji whose visual form was dictated by a pre-existing internet meme rather than the other way around.
Keywords: doubt, dunno, guess, idk, ignorance, indifference, knows, man, maybe, shrug, shrugging, whatever, who