Using a foreign language is suggested to affect how we think and decide, even reducing bias in our judgment. However, the exact mechanisms of its influence are still unknown. In this project, we tested two of the potential mechanisms driving the foreign language: increased cognitive reflection and greater task engagement. We analyzed previously collected data from 5 experiments employing the Cognitive Reflection Test and/or the Berlin Numeracy Test. The results show anecdotal to strong evidence supporting null effects. We believe that our results undermine the claim that using a foreign language promotes more cognitive reflection or engagement

The Foreign Language effect is claimed to decrease risk aversion. We found no such effect. First, we asked N = 229 Polish native speakers to assign numerical values to verbal probability phrases in Polish and English. After finding very few differences, we conducted an incentivized experiment, N = 281, where Poles had to decide whether they would prefer to receive a granted amount of money or take part in a lottery task where the chance of winning was expressed by the phrases from the pre-test. Regardless of the language, the participants made the same choices.

Using a foreign language is suggested to affect how we think and decide. However, the exact mechanisms of its influence are still unknown. In this project, we tested one of the potential mechanisms: increased cognitive engagement in a foreign language. If so, we would expect increased performance in cognitive ability tests, e.g., in numeracy, when administered in a foreign language. We conducted two experiments with n=415 participants, comparing performance in the Berlin Numeracy Test in a foreign versus native language. The results show anecdotal to strong evidence supporting null effects. We believe that our results undermine the claim that using a foreign language promotes more cognitive engagement.