Attrition as bias strengthening: revisiting previous findings from interface phenomena

The acquisition and use of a second language may impact a speaker’s first language, a phenomenon known as attrition . An area of particular interest for research on attrition has been the interpretation of subject pronouns in languages like Italian, which exhibit distinct biases for null and overt pronouns. That body of work has largely focused on overt pronouns, arguing that speakers’ biases for those forms weaken under attrition. However, we argue that previous results are more mixed than usually acknowledged; they also provide evidence that speakers undergoing attrition may exhibit a strengthening of their L1 (interpretive) biases more generally. To assess whether we should take this second trend seriously, the present paper investigates an apparent strengthening effect relating to null pronouns in Italian. For this, we conducted a sentence interpretation task with globally ambiguous sentences which included either a null or an overt pronoun. This task was presented to two groups of native Italian speakers, one in Italy and one in an English-speaking country. As predicted, results revealed a stronger interpretive bias for null pronouns under attrition. Therefore, we argue that theories of attrition should account for why speakers may exhibit not only a weakening of specific biases, but also a strengthening of their L1 biases more generally.