A STUDY OF THE EFFECTS OF PRINCIPAL BRANCHING DIRECTION IN SECOND LANGUAGE ACQUISITION: THE GENERALIZATION OF A PARAMETER OF UNIVERSAL GRAMMAR FROM FIRST TO SECOND LANGUAGE ACQUISITION

This study reports the results of a series of experimental studies which provide evidence that a significant linguistic principle argued to constrain first language (L1) acquisition also constrains adult second language (L2) acquisition. This principal, sensitivity to the Principal Branching Direction (PBD) or principal recursion direction of the language being acquired, is used by both L1 and adult L2 learners to constrain hypotheses about grammatical anaphora. This principle has been argued to involve a parameter, the value of which is initially set by L1 experience as either right or left, but which may need to be reset for some L2.;Results indicate that both the Spanish and Japanese Ss are sensitive to facts about embedding and anaphora in the L2. For the Spanish Ss, (L1PBD = L2PBD) production and interpretation is significantly facilitated over the Japanese Ss, (L1PBD (NOT=) L2PBD). Results suggest that the Japanese ss must revise hypotheses about PBD and anaphora direction and make them cohere with the value of the PBD of the L2 being acquired.;The results are argued to provide the basis for a theory of L2 acquisition which specifies that the essential language faculty (Universal Grammar) involved in L1 acquisition is also involved in L2 acquisition. This fact is used to explain why L2 learners, regardless of L1, maintain a sensitivity to certain facts about the L2 they are acquiring, viz., embedding and anaphora, and begin to specify in terms of the match/mismatch between the L1 and L2 values of the PBD parameter of how knowledge of the L1 influences L2 acquisition.;Results are discussed in terms of the beginning of an integration and explanation of previously isolated contrastive and creative aspects of L2 acquisition within a single unified theory.;Empirical results are provided by three production tests and one interpretation test which investigate the acquisition of complex sentence structures in English which vary in recursion direction and anaphora direction by two groups of adult L2 learners whose L1 varies on the PBD parameter. Fifty-one speakers of Spanish, principally a right branching language like English, and 53 speakers of Japanese, principally a left branching language, unlike either English or Spanish are tested.