Chapter 9. How Would You Know If There is a Bilingual Advantage?

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C. Nathan DeWall, University of Kentucky

David G. Myers, Hope College

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Note: You will be guided through the Intro, Design, Measure, Interpret, Conclusion, and Quiz sections of this activity. You can see your progress highlighted in the non-clickable, navigational list at the right.

Watch this video from your author, David Myers, for a helpful, very brief overview of the activity.

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So, how would you know if there is a bilingual advantage? To study this question in your role as researcher, you need to DESIGN an appropriate study that will lead to meaningful results, MEASURE some type of performance, and INTERPRET the larger meaning of your results, considering how your findings would apply to the population as a whole.

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Experiments:

Longitudinal and Cross-Sectional Studies:

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You have chosen Longitudinal Correlational design, which means you want to retest the same people over a period of years. For example, when testing whether having a natural, happy smile in a college yearbook predicts later marriage happiness, researchers measured facial expressions in a college yearbook and levels of marriage happiness in middle age (Harker & Keltner, 2001). This allowed researchers to determine whether having a natural, happy smile in college predicts marriage happiness years later. (It does.)

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Using the Longitudinal Correlational design, we might examine whether bilingual individuals, compared with those who are not bilingual, have more productive lives years later. But we would not know whether being bilingual caused the apparent advantage. Several factors can influence whether individuals learn a second language, including the ability to afford language lessons, having parents who speak more than one language, and other environmental factors. We need to determine whether systematically giving some people the opportunity to become bilingual, compared with those who are not given the same opportunity, causes a performance advantage.

So, LONGITUDINAL CORRELATIONAL IS NOT THE BEST RESEARCH DESIGN for this study.

Click “Next” to go back and try again to select the most effective research design.

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You have chosen Cross-Sectional Correlational as your design. With this type of design, researchers test and compare, at one point in time, people who have different characteristics.

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What could we learn from these participant choices?

a. A group of people who speak two languages fluently You would need to study individuals who speak two languages fluently, but you also need to be able to compare their responses with those who do not speak two languages fluently. By only studying bilingual individuals, you also would not be able to generalize your findings to the general population.

b. A group of people who speak one language fluently and are interested in becoming fluent in a second language Just because people express an interest in becoming bilingual does not mean that they are, or will ever become fluent in a second language. To know whether there is a bilingual advantage, you need to compare performance between groups of bilingual and monolingual individuals.

c. A group of people who have superior language abilities in their native language Studying this group of people would not give you the information you need about a possible bilingual advantage. To know whether there is a bilingual advantage, you need to compare bilingual people with people who are not bilingual.

d. A group of people who speak two languages fluently and a group of people who speak one language fluently You were correct to choose this option, because you could compare responses between those who are bilingual and those who are not bilingual. HOWEVER, you would not be able to determine whether being bilingual causes a performance advantage. For example, smarter people might have an easier time learning a second language, which could explain their performance advantage. To establish causality, you would need to randomly assign people to either a monolingual group or a bilingual group and then compare their performance.

Trying to choose a sample of participants helps us realize that the CROSS-SECTIONAL CORRELATIONAL STUDY IS NOT THE BEST RESEARCH DESIGN to test this question. We’d get more helpful results by randomly assigning people to either a monolingual group (where no second language would be learned) or a bilingual group (where a second language would be learned) and then comparing them on some measure of performance. This would help us determine whether there is a bilingual advantage.

Click “Next” to go back and try again to select the most effective research design.

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Nice work! You have correctly chosen to use an Experimental design for your study.

Next, you need to choose the most appropriate study participants.

With an experimental design, you need to set up experimental and control conditions. For example, when testing whether smiling increases happiness, researchers will have those in the experimental group smile, and those in the control group frown. Next, the researchers will measure all participants’ happiness levels. This allows researchers to determine whether people who smile, compared to those who frown, feel happier. (They do!)

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You chose A group of bilingual children who were randomly assigned to attend a language immersion school in their second language, and a group of bilingual children who were randomly assigned to attend a language immersion school in their native language, but this is NOT CORRECT. You need to compare later performance of individuals who are given the opportunity to become bilingual with those who are not given that opportunity. By only studying bilingual individuals, you also would not be able to generalize your findings to the larger population.

Click “Next” to try again to choose the most appropriate study participants.

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You chose A group of children who can speak one language fluently and were assigned to attend a language immersion school in a second language, but that is NOT CORRECT. You need to compare performance in individuals who are bilingual with those who are not bilingual. By only studying children who were randomly assigned to attend a language immersion school, you would not be able to compare their performance with those of children who were randomly assigned not to attend a language immersion school.

Click “Next” to try again to choose the most appropriate study participants.

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You chose A group of children who have superior language abilities in their native language, but that is NOT CORRECT. Studying this group of children would not give you the information you need about a possible bilingual advantage. To know whether there is a bilingual advantage, you need to compare bilingual people with people who are not bilingual.

Click “Next” to try again to choose the most appropriate study participants.

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Good job! You have correctly chosen to use an Experimental design, in which you will systematically change the opportunity participants have to become bilingual. By choosing an Experimental design, you will be able to determine whether being bilingual causes individuals to experience an advantage. You also chose an appropriate sample of participants—A group of children who were randomly assigned to attend a language immersion school in a second language, and a group of children who were randomly assigned not to attend a language immersion school in a second language. Now you need to determine how best to MEASURE the relevant behavior or mental process, which in this case is performance on some standard measure. For the purposes of this study, let’s focus on a measure of attention as our performance comparison.

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You chose Have participants listen to a recording that has a different voice presented to each ear. Ask them the following question: “How much did you enjoy the recording you heard?”(1=not at all to 7=quite a bit), but that is NOT CORRECT.

This option would not give you information about how well participants paid attention. It would only tell you how much they enjoyed the recording. To know whether there is a bilingual advantage, we have to measure actual performance on an assessment of attention.

Click “Next” to try again to select the best way to measure whether there is a bilingual advantage.

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You chose Have participants listen to bilingual students reading personal essays. Ask participants the following question: “How focused did the bilingual students seem while they read their essay?” (1=not at all to 7=quite a bit), but that is NOT CORRECT.

This option would not give you information about how well participants paid attention. Instead, you chose an option that would measure how participants perceived others’ attentional capacity. To know whether there is a bilingual advantage, we have to measure participants’ actual performance on an assessment of attention.

Click “Next” to try again to select the best way to measure whether there is a bilingual advantage.

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You chose Have participants listen to a recording that has a different voice presented to each ear. Ask them the following question: “Compared with the average student, how well did you pay attention to the material you heard?” (1=worse than the average student to 7=much better than the average student), but that is NOT CORRECT.

By choosing this option, you did not measure actual attention performance. Instead, you asked participants to estimate how well they paid attention. Our estimates aren’t always accurate. In fact, people usually think they’re above average! So, this would not be the best option. To know whether there is a bilingual advantage, we have to measure participants’ actual performance on an assessment of attention.

Click “Next” to try again to select the best way to measure whether there is a bilingual advantage.

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Nice job! You have correctly chosen to use an Experimental design, in which you will systematically change the opportunity participants have to become bilingual. By choosing an Experimental design, you will be able to determine whether being bilingual causes individuals to experience a performance advantage. You chose an appropriate sample of participants—a group of children who were randomly assigned to attend a language immersion school in a second language, and a group of children who were randomly assigned not to attend a language immersion school in a second language. You also chose how best to MEASURE the relevant behavior or mental process, which in this case is attention. You chose Have participants listen to a recording that has a different voice presented to each ear. Ask them to ignore information presented to their right ear and write down certain words presented to their left ear. Count how many words they correctly identify.

In several studies, researchers have in fact identified what they call a bilingual advantage (Lambert et al., 1993). One skill that bilingual individuals develop, of necessity, is the ability to inhibit one language while using another. That effort requires more attentional capacity than is needed for keeping track of only one language. This bilingual attentional advantage spills over into other areas of life, such as having a greater ability to ignore distracting information (Bialystock & Craik, 2010). Even 7-month-old babies, who have yet to speak their first word, show an attentional advantage when raised in bilingual homes (Emmorey et al., 2008; Kovacs & Mehler, 2009). Other work has shown that bilingual individuals also experience less cognitive decline later in life (Lazaruk, 2007).

Knowing this, you need to consider how you can apply what you’ve learned to the larger population—beyond the people you’ve studied. Consider where you might encounter roadblocks to confidence in your results. What factors might keep you from being able to apply what you’ve learned in a broader context?

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You tested whether there is a bilingual advantage. You measured how well bilingual individuals, compared with monolingual individuals, paid attention. Several factors could affect attention, and they might not have any relation to whether people speak more than one language! Such factors that could interfere with your INTERPRETATION of results are called confounding variables.

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Confounding Variables:

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The confounding variables for your study would include those highlighted below:

The highlighted confounding variables would relate to your confidence in whether there is a bilingual advantage. You are comparing participants who enroll in a language immersion school with those who do not enroll. But you need to make sure that participants actually become bilingual. Otherwise, you would not know whether your results are due to an actual bilingual advantage. You also need to determine whether participants were bilingual before they started the study. If some participants were already bilingual, that might affect your results. Even having a high number of bilingual relatives could affect a participant’s performance. Finally, you need to identify participants who may have difficulty paying attention, such as those who have a diagnosis of ADHD. By keeping track of how well participants can pay attention, you will have more confidence that your results are due to a bilingual advantage and not some other cause.

Note that by randomly assigning participants to either enroll in a language immersion school, or not enroll in a language immersion school, you control for many other possible confounding variables. With random assignment, each participant has the same chance of being assigned to each group. This should give each of your groups a balanced number of participants expressing these variations.

Click on "Video Hint" below to see a brief animation describing Random Assignment.

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Random Assignment:

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You may do better on the Quiz if you take notes while watching this video. Feel free to pause the video or re-watch it as often as you like.

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