Beauvois and Joule (1981) attempt to explain the reasons for theescalation ‘We are only committed through our actions. We are not committed through our ideas, our feelings, but by our actual behaviour. The individual rationalises his or her behaviours by endorsing, retroactively, ideas designed to justify them.’ This type of retroactive discourse to justify the individual’s behaviour will be progressively internalised and contribute to convince the individual that his or her new opinion is founded.