The phenomenon of styleswitching has been important in the study of L1 and L2 language use. Labov's early studies correlated formal style with attention paid to speech, a notion echoed in Krashen's monitor model. Giles' accommodation theory and Bell's audience design theory claim that speakers styleswitch in order to accommodate to the speech of their audience. Several SLA scholars have found evidence for accommodation in L2 speech as well. Such correlational studies have been criticized for lacking a clear foundation in cognitive theory. In this volume Myers-Scotton describes her Markedness Model (MM), which grounds styleswitching (including codeswitching) in the cognitive theory of somatic markers (Damasio, 1994). Because speech styles are distinguished mainly by the frequency at which certain features (such as dropping a consonant from a cluster) appear, variationists have sought to identify a cognitive mechanism that could account for the apparent fine-tuning of feature frequencies. However, it is not clear from the discussion in this volume whether the somatic marker hypothesis provides such a mechanism.