Markedness Differential Hypothesis

The Markedness Differential Hypothesis (MDH), proposed by Fred Eckman (1977), predicts that areas of the target language that are both different from the L1 and more typologically marked will be difficult for L2 learners, while areas that are different but less marked will not. The hypothesis was an explicit attempt to strengthen the Contrastive Analysis Hypothesis (CAH) by incorporating the linguistic concept of markedness, which provides a principled, language-independent measure of difficulty.

The Problem with Contrastive Analysis

The original CAH (Lado, 1957) predicted that L1-L2 differences cause difficulty. But this prediction is symmetrical: if language A differs from language B in some feature, the CAH predicts equal difficulty in both directions. Empirically, this is often false. For example, a speaker of a language without voiced final obstruents (e.g., German) learning a language with them (e.g., English) faces more difficulty than the reverse. Eckman's insight was that directionality of difficulty can be explained by markedness.

Definition of Markedness

Eckman adopted a typological definition: a phenomenon A is more marked than a phenomenon B if the presence of A in a language implies the presence of B, but not vice versa. For example, voiced obstruents in syllable-final position are more marked than voiceless obstruents in the same position, because any language that has final voiced obstruents also has final voiceless obstruents, but not the reverse.

The Hypothesis

Eckman (1977, p. 321) stated the MDH as three predictions:

1. Areas of the L2 that differ from the L1 and are more marked than the L1 will be difficult
2. The relative degree of difficulty corresponds to the relative degree of markedness
3. Areas of the L2 that differ from the L1 but are not more marked will not be difficult

This asymmetry is the key advance over Contrastive Analysis. The MDH predicts difficulty only where the L2 is more marked than the L1, not simply where the two languages differ.

Evidence

The MDH has been most extensively tested in phonology:

• Voice contrast in final position — learners whose L1 lacks final voiced obstruents (e.g., German, Mandarin) have documented difficulty acquiring them in English, as predicted. Learners moving in the other direction (from a language with the contrast to one without) do not face the same difficulty.
• Consonant clusters — languages with more complex syllable structures (more marked) are harder to acquire for speakers of languages with simpler structures.
• Relative clauses — the Accessibility Hierarchy (Keenan & Comrie, 1977) shows that more marked relative clause types (e.g., object of comparison) are harder to acquire than less marked types (e.g., subject relatives), consistent with MDH predictions.

Limitations

• The MDH works well for phonology but has been less consistently supported in syntax and morphology
• It does not account for all L2 difficulty — some errors arise from processing constraints, transfer of training, or communicative strategies, not from markedness
• The definition of markedness itself is debated — typological frequency, structural complexity, and acquisition order do not always converge

Later Development

Eckman (1991) extended the approach with the Structural Conformity Hypothesis, which predicts that interlanguage systems obey the same typological universals as natural languages — even structures produced by transfer or overgeneralisation will tend to conform to universal markedness patterns. This broadened the theoretical scope beyond L1-L2 comparison to the nature of Interlanguage itself.