A linear scale has compliments at one end (1) and insults at the other (10). Some material reaches the six range. Purpose: let a girl know you're not impressed. Show her you're impressed and she perceives her value too high. Sex withholding follows. Context matters. "You're too old for me" is a joke when playful but offensive if discussing politics. If she's already joking with you, she knows it's personality. For marriage prospects, calibrating humor shows intelligence.