The heated debate regarding bilingual cognitive advantages remains ongoing. While there are many studies supporting positive cognitive effects of bilingualism, recent meta-analyses have concluded that there is no consistent evidence for a bilingual advantage. In this article we focus on several theoretical concerns. First, we discuss changes in theoretical frameworks, which have led to the development of insufficiently clear theories and hypotheses that are difficult to falsify. Next, we discuss the development of looking at bilingual experiences and the need to better understand language control. Last, we argue that the move from behavioural studies to a focus on brain plasticity is not going to solve the debate on cognitive effects, especially not when brain changes are interpreted in the absence of behavioural differences. Clearer theories on both behavioural and neural effects of bilingualism are needed. However, to achieve this, a solid understanding of both bilingualism and executive functions is needed first.