Dentella Vittoria, Masullo Camilla, Leivada Evelina
Department of English and German Studies, Universitat Rovira i Virgili, Tarragona, Spain.
Department of Catalan Philology, Universitat Autònoma de Barcelona, Barcelona, Spain.
Sci Rep. 2024 Jan 24;14(1):2107. doi: 10.1038/s41598-024-52417-5.
Bilingualism is linked to both enhanced and hampered performance in various cognitive measures, yet the extent to which these bilingual advantages and disadvantages co-occur is unclear. To address this gap, we perform a systematic review and two quantitative analyses. First, we analyze results from 39 studies, obtained through the PRISMA method. Less than 50% of the studies that show up as results for the term "bilingual disadvantage" report exclusively a disadvantage, that shows bilinguals performing worse than monolinguals in a task. A Bayesian analysis reveals robust evidence for bilingual effects, but no evidence for differences in the proportion of advantages and disadvantages, suggesting that when results from different cognitive domains such as executive functions and verbal fluency are analyzed together, bilingual effects amount to a zero-sum game. This finding was replicated by repeating the analysis, using the datasets of two recent meta-analyses. We propose that the equilibrium we observe between positive and negative outcomes may not be accidental. Contrary to widespread belief, advantageous and disadvantageous effects are not stand-alone outcomes in free variation. We reframe them as the connatural components of a dynamic trade-off, whereby enhanced performance in one cognitive measure is offset by an incurred cost in another domain.
双语能力与各种认知测试中的表现提升和表现受阻都有关联，然而这些双语优势和劣势同时出现的程度尚不清楚。为了填补这一空白，我们进行了一项系统综述和两项定量分析。首先，我们分析了通过PRISMA方法获得的39项研究的结果。在显示为“双语劣势”一词结果的研究中，不到50%的研究仅报告了劣势，即双语者在一项任务中的表现比单语者差。贝叶斯分析揭示了双语效应的有力证据，但没有证据表明优势和劣势的比例存在差异，这表明当对执行功能和语言流畅性等不同认知领域的结果进行综合分析时，双语效应相当于一场零和博弈。通过使用两项近期荟萃分析的数据集重复分析，这一发现得到了验证。我们认为，我们观察到的正负结果之间的平衡可能并非偶然。与普遍看法相反，优势和劣势效应并非自由变化中的独立结果。我们将它们重新定义为一种动态权衡的固有组成部分，即在一种认知测试中表现的提升会被另一个领域产生的成本所抵消。
