From Group Results to Individual Patterns in Pronoun Comprehension Jacolien van Rij, Petra Hendriks, Jennifer Spenader & Hedderik van Rijn University of Groningen 1. Delay of Principle B Effect A well-studied phenomenon in language acquisition is the acquisition of pronouns and reflexives (e.g., Chien & Wexler, 1990; Jakubowicz, 1984; Koster, 1993; Philip & Coopmans, 1996; Spenader, Smits, & Hendriks, 2009). The adult use of reflexives and pronouns can be described by Principles A and B of Binding Theory (Chomsky, 1981). (1) a. Principle A: a reflexive must be bound in the local domain. b. Principle B: a pronoun must be free in the local domain. Here, the local domain is defined as the minimal clause that contains both the lexical anaphor and a subject. An anaphor is bound when it is co-indexed with and c-commanded by an antecedent. To illustrate the application of the binding principles, consider sentences (2a) and (2b). (2) a. The penguin i is hitting himself i/*j with a pan. b. The penguin i is hitting him *i/j with a pan. According to Principle A, the reflexive himself in (2a) has to co-refer with the subject of the local domain, the penguin. Principle B states that a pronoun must be locally free, which means that a pronoun cannot co-refer with the subject in the local domain. As a result, the pronoun him in (2b) cannot co-refer with the penguin, but must refer to another antecedent present in the context. Given the similarity between Principles A and B, it is expected that the acquisition of reflexives and pronouns proceeds at a comparable speed. However, although children show adult-like performance on reflexive comprehension from the age of 3;0 on, they have been shown to experience difficulties in the interpretation of pronouns up to the age of 6;6 by incorrectly allowing the pronoun to corefer with the local subject (e.g., Chien & Wexler, 1990). This delay in the acquisition of pronoun comprehension is called the Delay of Principle B-Effect (DPBE). On the other hand, it has recently been shown that children can produce reflexives and pronouns correctly from the age of 4;6 on (e.g., De Villiers, Cahillane, & Altreuter, 2006; Spenader et al., 2009). So there seems to be a second asymmetry in the acquisition of pronouns, namely between comprehension and production. As yet there is no general consensus on what causes these