People sometimes fail to notice that the second sentence actually means the opposite of the first: our comprehension abilities may not be as good as one assumes they are. Research has shown that implausible sentences with more complex structures are sometimes misunderstood in favour of the more plausible option.

For some twenty years now, the phenomenon known as good-enough processing has been studied to understand why we sometimes fail to correctly understand and process what we hear. Good-enough processing in fact refers to the notion that we process the input well enough to get by, but without carefully checking whether the interpretation we reach is the correct one. A similar error happens in the Moses illusion: when asked “How many animals of each kind did Moses take on the ark?” people tend to overlook that it was Noah, not Moses, to take animals on the ark, and answer the question with “two”. However, misinterpretations are most common with more complex sentences. For example, when reading the sentence “the dog bites the man” we almost always reach the correct (painful) interpretation. The same goes for the opposite sentence, “the man bites the dog”; we have no trouble in correctly processing this sentence, even though it describes an implausible situation. However, the harder sentence “the dog is bitten by the man” is sometimes misinterpreted as the dog biting the man. This misinterpretation occurs a surprising 20-30% of the time for sentences with this more complex word order (i.e. in passive voice).

Why might this be? One view suggests that during listening we use simple heuristics, or quick and dirty interpretations, to reach a plausible meaning quickly. For example, in the sentence “the dog was bitten by the man”, the first noun, the dog, is assumed to be the doer (or agent) of the action, and the man the entity to which the action is done, even though the passive structure signals that the opposite is true. Full processing of the word order (syntactic processing) occurs in parallel and more slowly, and sometimes may not be completed.

The good news is that this is unlikely to affect our everyday life, because information is usually exchanged in context, which can help heuristic processing. For example, when saying something implausible, the speaker knows that it’s better to add emphasis to ensure the listener understands. Moreover, just as listeners do not always understand correctly, speakers also sometimes make mistakes when speaking: the implausible meaning might be the speaker’s error, which listeners know to overlook. So, even though our communication system is not always perfect, it does well enough to ensure mutual understanding.

Further reading

Ferreira, F. (2003). The misinterpretation of noncanonical sentences. Cognitive psychology47(2), 164-203.

Ferreira, F., Bailey, K. G., & Ferraro, V. (2002). Good-enough representations in language comprehension. Current directions in psychological science11(1), 11-15.

Ferreira, F., & Lowder, M. W. (2016). Prediction, information structure, and good-enough language processing. In Psychology of learning and motivation (Vol. 65, pp. 217-247). Academic Press.