I’ve always been amazed by people who are truly bilingual. While I’ve studied languages in school, I’ve never been able to seamlessly switch between languages, and even my best non-English language, French, is choppy at best. Compare this to the people I see in restaurants or on the subway, who can have conversations in two languages at once, speaking each language with equal fluency. They might tell a story in English, but save the punch line for Spanish. If a monolingual person talks to them, they instantly respond in the proper language, with hardly a second thought.
There are enough bilingual people in the world to suggest that they don’t have some special ability that the rest of us lack; they’ve simply had more practice than others and learned it at a young enough age to
avoid an accent achieve mastery. Some children are taught one language at home and another at school, or their parents each speak different languages, so they learn both. But still, the difference between monolingual and bilingual individuals is dramatic enough that you’d expect to find differences in other aspects of their behavior.
In fact, some researchers have found that bilinguals are better at certain tasks than non-bilinguals. One example is the Simon task, where two objects are flashed on the screen side-by-side. Respondents might press a button on the left when one of the objects is red and a button on the right when one of the objects is green. Bilinguals are better at the task than monolinguals when the object in question is on the opposite side of the button they have to push (for example, the green object is on the left but you have to press the right-hand button to indicate “green”).
This makes some sense — after all, a person who speaks both English and Spanish has had a lot of practice not speaking the wrong language, which may be similar to not pressing the wrong button.
But if it’s possible for bilinguals to have better performance at some tasks, it’s also possible that they might be worse at some things too. Consider the following movie:
A team led by Barbara Treccani showed students a set of movies similar to this; they were instructed to ignore the Os and click one of four different buttons to indicate which position each X appeared in. The trick with these movies is that sometimes the Os acted as negative primes: If an O appears in a spot where the X later appears, then the act of ignoring the O on one screen makes it harder to spot the X on the next screen.
In fact, every display was coordinated: the first two Xs and Os in our example appeared in spots where there had been no letter before, so there was no priming at all for either Xs or Os. The fourth X, on the other hand, appeared in a spot where an O had been before: This is a case of negative priming.
Treccani’s team showed 29 bilingual and 29 monolingual students movies like this (with the Xs and Os appearing in dozens of random, different positions) and measured accuracy and reaction time. Here are some of the results:
In cases where there was no priming, bilinguals made significantly fewer errors than monolinguals: just as in the Simon task, they were better at ignoring irrelevant information.
But in negative priming trials, where the O appeared in the same spot as the X on the next screen, bilinguals made significantly more mistakes than monolinguals. However, the results were complicated. In some other trials, there was no difference between bilingual and monolingual respondents. And in no cases did one group react faster than the other group, so these results are less clear-cut than the earlier Simon task results.
Nonetheless, it’s an interesting finding that bilinguals don’t always experience a cognitive advantage over monolinguals. The discipline it takes to seamlessly switch from one language to another can also make some tasks a little more different for bilinguals.
Treccani, B., Argyri, E., Sorace, A., & Sala, S. (2009). Spatial negative priming in bilingualism Psychonomic Bulletin & Review, 16 (2), 320-327 DOI: 10.3758/PBR.16.2.320
[Note: I used a different movie format for this post--MPEG-4, which should work better on computers that don't have QuickTime. I've added a poll below so we can see if this is working well. Or you can let me know how it works in the comments.]