Boundaries of the foreign language effect under conditions of uncertainty

People's decisions may change when made in a foreign language (FL). Research testing this foreign language effect (FLE) has mostly used scenarios where uncertainty is expunged or reduced to a form of risk, whereas real-life decisions are usually characterized by uncertainty around outcome likelihood. In the current work, we aimed to investigate whether the FLE on decision-making extends to uncertain scenarios. Moreover, as it is still unclear what linguistic and psychological factors contribute to the FLE, we tested the effects of participants' FL background, cognitive style and risk-taking attitude on decision processes under certain and uncertain conditions. Overall, we report null effects of language context (native versus foreign language) and problem condition (certain versus uncertain prospects) on participants' choices. In addition, we found that both FL background and decision makers' traits modulated participants' choices in a FL, without emerging into the 'classic' FLE on decision-making. However, the direction of such effects was complex, and not always compatible with previous FLE theories. In light of these results, our study highlights the need to reconceptualize the FLE and its implications on decision-making.