M. Wiener et al. called their article “Nonverbal behaviour and non-verbal communication”, and the distinction is important: not all non-verbal behaviour can be regarded as communicative. The term communication also poses problems of definition, particularly with respect to what behaviours can be properly regarded as communicative. Wiener et al. also challenge the view that the only non-verbal behaviours that can be regarded as communicative are those that are intended as such. Indeed, non-verbal communication may take place even against the express intentions of the encoder. Non-verbal cues can be said to communicate information about emotion, speech, individual differences, and interpersonal relationships; their significance also needs to be considered in specific social contexts. The central importance of non-verbal cues in the communication of emotion has led some writers to regard body movement as an alternative system to speech, offering a more reliable indicator of people’s true feelings.