Robert Bley-Vroman

Robert Bley-Vroman is Professor Emeritus at the University of Hawai'i at Mānoa, and the author of one of the most-cited theoretical proposals in SLA: the Fundamental Difference Hypothesis. First stated in a 1989 chapter and sharpened in a 1990 Linguistic Analysis paper, the FDH argues that adult second-language acquisition is qualitatively different from child first-language acquisition, because adults have lost the domain-specific parameter-setting machinery and fall back on general problem-solving applied to L2 input.

The claim is narrower and more carefully argued than the slogan suggests, which is why it has survived. Bley-Vroman's 2009 "The Evolving Context of the Fundamental Difference Hypothesis" in Studies in Second Language Acquisition restates the position without insisting on a fully domain-specific L1 module, shifting the focus to qualitative differences in grammatical processing between L1 and adult L2 systems. It remains the cleanest articulation of why generative SLA and age-of-acquisition research cannot simply fold L2 back into L1.

Career

• Professor, University of Hawai'i at Mānoa (now Emeritus)
• Long collaboration with Hawai'i SLA colleagues on L2 syntax, processing, and age effects

Published Work

• "The logical problem of foreign language learning," Linguistic Analysis (1990)
• "What is the logical problem of foreign language learning?" in Gass and Schachter (eds.), Linguistic Perspectives on Second Language Acquisition (1989)
• "The evolving context of the Fundamental Difference Hypothesis," Studies in Second Language Acquisition (2009)
• Papers on L2 dative alternation, argument structure, and near-native grammar

Influence

• Gave UG-based SLA its cleanest explanation for why adult L2 outcomes look different from L1
• A constant reference for critical-period debates, age-of-acquisition research, and the generative-emergentist argument
• Cited across both sides of the UG debate as the position to argue against