Memo to restaurant owners: if there are particular dishes you want more customers to order, list them on the right side of the menu.

If you read my recent column on how language affects thinking, you're probably not at all surprised that the word "right" has not only a spatial meaning but also connotations about morality and correctness and even, it turns out, taste appeal. It isn't for nothing that we speak about "the right answer" and not the left one, why the Latin dexter (right) gives us "dexterous" but the Latin sinister (left) gives us, well, "sinister." But there's a fascinating exception to the power of language to affect thought. Even though they live in a world dominated by right-handers, with all the good/bad connotations of right/left, left-handers associate left with good and right with bad. Simply put, we associate the side of space where we're clumsier with bad, stupid, dishonest, unhappy and other negative qualities, finds Daniel Casasanto of the Max Planck Institute for Psycholinguistics in the Netherlands.

In a series of five clever studies, reported Aug. 1 in the Journal of Experimental Psychology: General, he had university students take tests probing their unconscious attitudes toward the left and right side of the world. In one, 219 students from Stanford University and the University of California, Riverside, were told that a cartoon character loves zebras but hates pandas (or vice versa). On a paper with two boxes side by side, they had to draw a zebra in one and a panda in the other. A majority (74 percent) of left-handers drew the "good" animal in the box on the left, while most (67 percent) of the right-handers drew the good animal in the box on the right. Digging deeper into the statistics, it turns out that right-handers were nearly six times more likely than lefties to place the good animal on the right and the bad animal on the left. "Right-handers' responses were consistent with the mental metaphor Good Is Right, and left-handers' with the mental metaphor Good Is Left," says Casasanto.

In my favorite experiment, Casasanto showed 286 student volunteers pictures of "Fribbles"  (aliens from the planet Fribbalia, of course) arrayed in two columns, side by side on a page. Between each pair was an instruction, such as "Circle the Fribble who looks more intelligent"—or more attractive, more honest, happier, less intelligent, less attractive, less honest, sadder. Of the participants who showed a directional preference, most left-handers (65 percent) attributed positive characteristics more often to Fribbles on the left, while most right-handers (54 percent) attributed positive characteristics more often to Fribbles on the right. Statistical analysis showed that righties were about twice as likely as southpaws to attribute positive characteristics to Fribbles on the right side.

In another test, Casasanto had 371 volunteers read brief descriptions of products (mattresses, desk chairs, kiddie pools) on the left or right side of a page and then indicate which they'd like to buy. Again, most righties chose the product described on the right side, but most lefties—resisting whatever implicit message the righty culture conveys—chose the item on the left. And when volunteers read about two job candidates whose resumes were printed side-by-side, right-handers tended to choose the person described on the right, but left-handers chose the one on the left, again being unconsciously swayed by their experience of space more than the conventions of language and culture.

The findings are curious for several reasons. The first is that they point out that words are not all-powerful in shaping thought, but that's no surprise. More interesting is that cognitive scientists have long thought that since the regions of the brain that process our perceptions of the physical world are distinct from the regions that process abstract concepts—good and bad, honest and dishonest, smart and stupid—our spatial perceptions would have no effect on abstract thinking. Casasanto's findings support a competing idea, namely, that neuronal circuits that control concrete perceptions and actions also handle abstract thoughts.

He calls it the Body-Specificity Hypothesis. And it implies that people with different physical characteristics, such as being right- or left-handed, form different abstract concepts, corresponding to those physical traits. For southpaws, the left side of any space has positive moral, intellectual, and emotional connotations; for righties, the right side does. What Casasanto calls "these contrasting mental metaphors" cannot be "attributed to linguistic experience," he points out, "because idioms in English associate good with right but not with left. [But] right- and left-handers implicitly associated positive [values] more strongly with the side of space on which they could act more fluently with their dominant hands." That influence is stronger than the linguistic cues we get every day about "right-hand man," "the right side of history," "out in left field," or "two left feet." And what explains the cultural predominance of right = good? The predominance of righties throughout history and across cultures.

I was serious about the menu placement. As Casasanto says, "even subtle influences of spatial location could have measurable real-world consequences," and menu choices are the least of them. The placement of candidates on a ballot? Of items in a catalog? "If we want to win approval, garner customers, or accumulate votes," he says, "the right side may be the right place to be."

© 2009