But you may not need glasses if you’re beautiful. A Czech study found that certain facial features—narrow faces, long noses, and thin chins—correlated with both perceived intelligence and attractiveness. Interestingly, men who were considered smart-looking actually tended to have higher IQs; the same was not true for women [1].

Other ways to signal intelligence without opening your mouth include walking at the same pace as those around you. Subjects in one study rated a person moving faster or slower than “normal human walking speed” as less competent and intelligent [2]. Speaking of incompetence: don’t drink in public, at least not at work functions. The perceived association between alcohol and stupid behavior is so strong, according to a 2013 study, that merely holding a beer makes you appear dumber [3].

How you write matters, too—particularly how you write your name. Middle initials apparently lend a person a certain cachet.