In the present study 36 university students were asked to read behaviour-descriptive sentences either under memory instructions or under behaviour-categorization instructions. It was demonstrated that after reading sentences under memory instructions sentence recall cued by a corresponding trait adjective was better than sentence recall cued by a strong semantic associate of a sentence part. This was found despite the fact that no actors were mentioned in the sentences. This result suggests that the spontaneous encoding of sentences in trait terms during the first stage of processing behavioural information has to be interpreted as the categorization of actions rather than as the attribution of traits to actors. This categorization of a behaviour is less pronounced when it occurs spontaneously than when explicit instructions are given to do so. The impact of the occurrence of spontaneous behaviour categorization on memory-based seq- or other ratings with concrete behaviour-descriptive items is discussed.