Theoretical Pluralism in SLA: Is There a Way Forward?

Abstract

In 1990 Long published a well-received article entitled ‘The least a second language acquisition theory needs to explain’. His idea was to establish a set of ‘facts’ that any theory of second language (L2) acquisition would need to explain and, thereby, provide an empirical basis for evaluating the plethora of theories that were current at that time. Such an approach is admirable, as perhaps the one evaluation criterion that all SLA researchers would sign up to is the need for a theory to be compatible with established empirical findings. The problem, of course, is that the ‘facts’ themselves are often in dispute. While it is often possible to agree on broad generalisations (for example, ‘age differences systematically affect how successful learners are in learning an L2’), it is less easy to reach agreement on more specific statements (such as ‘there is a critical period for learning an L2, beyond which it is not possible to achieve native speaker competence’). While some researchers (DeKeyser 2000) claim the existence of a critical period has been clearly established, others (for example Bialystok and Hakuta 1999) dispute its existence while yet others (for example Birdsong 1999) have changed their opinion over time. Even apparently well-established facts have been challenged. For example, Lantolf (2005) queried the existence of acquisition orders and sequences.