"Does your language shape how you think?" Linguists have gone back and forth on this question, explains Guy Deutscher in The New York Times. Back in 1940, an article by anthropologist Benjamin Lee Whorf floated the notion that "our mother tongue restricts what we are able to think." Not having markers for future or past tense, for example, would keep us from being able to comprehend the future and past. But that pretty clearly isn't true, says Deutscher, and "Whorf's theory crash-landed on hard facts and solid common sense, when it transpired that there had never actually been any evidence to support his fantastic claims."

Still, Deutscher presents a number of recent findings suggesting that our mother-tongue does have some effect. It may lie, for example, in what it forces us to think about: for example, English does not "habitually [oblige]" its speakers to consider gender. Its speakers "do not have to consider the sexes of neighbors, friends, teachers and a host of other persons each time they come up in a conversation, whereas speakers of some languages are obliged to do so." Likewise, English speakers do not think of chairs as masculine or feminine, although a Spanish or French speaker might. It turns out that this does have an effect:

In recent years, various experiments have shown that grammatical genders can shape the feelings and associations of speakers toward objects around them. ... When speakers were asked to grade various objects on a range of characteristics, Spanish speakers deemed bridges, clocks and violins to have more "manly properties" like strength, but Germans tended to think of them as more slender or elegant.
Then there's the matter of color: "green and blue are distinct colors in English but are considered shades of the same color in many languages." Bizarrely, it turns out that "our brains are trained to exaggerate the distance between shades of color if these have different names in our language." Even more dramatic is the effect that language seems to have on conceptions of space. There are some languages that do not use "egocentric" directional markers, such as left, right, behind, and ahead. Instead, they say "eastward" or "northward." As a result, they "need to know where the cardinal directions are at each and every moment." This ends up changing how the speakers of these languages think:
Indeed, speakers of geographic languages seem to have an almost-superhuman sense of orientation. Regardless of visibility conditions, regardless of whether they are in thick forest or on an open plain, whether outside or indoors or even in caves, whether stationary or moving, they have a spot-on sense of direction. They don't look at the sun and pause for a moment of calculation before they say, "There's an ant just north of your foot."
So while the old theory about mother tongues restricting one's "capacity to reason" is wrong, Deutscher concludes that it's also a mistake to suppose that everyone thinks the same way. "As a first step toward understanding one another," he writes, "we can do better than pretending we all think the same."