Previous research has shown that bilingual speakers may be more tolerant to ambiguity, they might perceive situations of ambiguity more interesting, challenging and desirable (e.g., Dewaele & Li, 2013). To our knowledge, no data are available addressing the question whether the language in use can have an effect on the personality trait of tolerance of ambiguity (ToA). This study investigated whether and how reading statements in a second language (L2), as opposed to the native language (L1), affects ToA. 387 Italian–English bilingual adults completed a questionnaire measuring levels of ToA either in English or Italian. Results revealed that processing information in L2 promoted higher scores of ToA overall and in sentences that were related to challenging perspectives and change. Age, gender and L2 proficiency were significant predictors of higher ToA scores. This study offers new evidence that processing information in a L2 can affect tolerance of ambiguous situations.

The relationship between multilingualism and tolerance of ambiguity (TA) has been examined in recent studies (e.g., Dewaele & Li, 2013; van Compernolle, 2016), which focus upon multilinguals with mixed nationalities in non-EFL contexts. Most of these studies regrettably reflect a failure to use effect sizes or provide information on the reliability and validity of the instruments used. The present study explored the relationship between multilingualism and TA by focusing upon 260 English-using multilinguals of one single nationality in an EFL context. Factor analysis revealed a three-factor solution, rather than a four-factor solution of the original TA scale, suggesting a need to re-examine the validity of such instruments when used outside of their native contexts. The results identified multilingualism, number of languages known and gender as important predictors for TA. Given the relative nature of effect-size benchmarks, a topic-specific effect-size benchmark system is proposed to (re-)interpret the present and previous findings.

The present study investigates the link between multilingualism and the personality trait Tolerance of Ambiguity (TA) among 2158 mono-, bi- and multilinguals. Monolinguals and bilinguals scored significantly lower on TA compared to multilinguals. A high level of global proficiency of various languages was linked to higher TA scores. A stay abroad of more than three months was also linked to higher TA although the effect levelled off after one year. Growing up in a multilingual family had no effect on TA. These findings show that a high level of multilingualism makes individuals more at ease in dealing with ambiguity, but we acknowledge that a higher level of TA can also strengthen an individual's inclination to become multilingual.