Perhaps these results are speculative all around, but I am happy to report them for your consideration:
Another strategy identified by the survey, wearing glasses, appears to be surprisingly effective. Figures released in 2011 by the College of Optometrists, in the U.K., show that 43 percent of the people it surveyed believe glasses make a person look more intelligent.
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.
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. 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.
How you write matters, too—particularly how you write your name. Middle initials apparently lend a person a certain cachet. Participants in a study published this year rated writing samples more favorably when the author’s name included a middle initial; they also presumed people with middle initials to be of higher social status than their uninitialed peers. Typing your initial in the Comic Sans font, though, could ruin the whole thing: a Princeton researcher found that a hard-to-read font made an author seem dumber, while a clean, simple typeface (Times New Roman, in the study) made him or her seem more intelligent.
The same researcher also looked at how using big words (a classic strategy for impressing others) affects perceived intelligence. Counterintuitively, grandiose vocabulary diminished participants’ impressions of authors’ cerebral capacity. Put another way: simpler writing seems smarter.