Tag Archives: Publication bias

Questions about the bilingual advantage

9 Dec

I have written a number of times about evidence that bilingualism may be protective against dementia. More narrowly, there has also been evidence that bilingual individuals have an advantage in executive control tasks. Now a paper in Psychological Science raises the possibility that that the latter claim may  a consequence of publication bias:

 “It is a widely held belief that bilinguals have an advantage over monolinguals in executive-control tasks, but is this what all studies actually demonstrate? The idea of a bilingual advantage may result from a publication bias favoring studies with positive results over studies with null or negative effects. To test this hypothesis, we looked at conference abstracts from 1999 to 2012 on the topic of bilingualism and executive control. We then determined which of the studies they reported were subsequently published. Studies with results fully supporting the bilingual-advantage theory were most likely to be published, followed by studies with mixed results. Studies challenging the bilingual advantage were published the least. This discrepancy was not due to differences in sample size, tests used, or statistical power. A test for funnel-plot asymmetry provided further evidence for the existence of a publication bias.”

Here is a summary of the paper.

“Ultimately, the findings suggest that the commonly accepted view that bilingualism confers a cognitive advantage may not accurately reflect the full body of existing scientific evidence.
According to de Bruin, these findings underscore how essential it is to review the published scientific literature with a critical eye, and how important it is that researchers share all of their findings on a given topic, regardless of the outcome.”

 

 

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