Previous research has shown that using foreign languages reduces cognitive biases. Here, we investigate whether this foreign-language effect extends to self-related cognition – in particular, the self-positivity bias, which refers to automatic association of oneself with positive information and has a facilitation role in maintaining mental health. We applied event-related brain potentials and oscillations in the implicit association test where Chinese–English bilinguals responded to category words (self vs. others) and attribute words (positive vs. negative) in either their native language Chinese or their foreign language English. In response to Chinese words, a self-positivity bias occurred, indexed by a positive D-score in reaction times as well as by smaller N200, larger P3-like/LPC responses, and lower alpha desynchronization when self words were associated with positive relative to negative traits. However, the bias was diminished in the English context. Overall, our findings provide important implications for language choices when self-protective mechanisms should be enhanced.
