Causal connectives in discourse processing: How differences in subjectivity are reflected in eye movements

Causal connectives are often considered to provide crucial information about the discourse structure; they signal a causal relation between two text segments. However, in many languages of the world causal connectives specialise in either subjective or objective causal relations. We investigate whether this type of (discourse) information is used during the online processing of causal connectives by focusing on the Dutch connectives want and omdat, both translated by because. In three eye-tracking studies we demonstrate that the Dutch connective want, which is a prototypical marker of subjective CLAIM–ARGUMENT relations, leads to an immediate processing disadvantage compared to omdat, a prototypical marker of objective CONSEQUENCE–CAUSE relations. This effect was observed at the words immediately following the connective, at which point readers cannot yet establish the causal relation on the basis of the content, which means that the effect is solely induced by the connectives. In Experiment 2 we demonstrate that this effect is related to the representation of the first clause of a want relation as a mental state. In Experiment 3, we show that the use of omdat in relations that do not allow for a CONSEQUENCE–CAUSE interpretation leads to serious processing difficulties at the end of those relations. On the basis of these results, we argue that want triggers a subjective mental state interpretation of S1, whereas omdat triggers the construction of an objective CONSEQUENCE–CAUSE relation. These results illustrate that causal connectives provide subtle information about semantic-pragmatic distinctions between types of causal relations, which immediately influences online processing.