The study of the socio-psychological processes involved in persuasion is onethe pivotal topics in social psychology. Eight decades ago, researchers from Yaleuniversity were the first in studying the mechanism of persuasion in the specificcontext of World War ll. Persuasion is obtained when the receptor of communicationmakes a change in his mind that is when a change in attitude occurs. Logically, such achange in attitude should imply a change in behavior. The research on behavioralchange show that it is not systematically the case. Thus changing what people think isnot changing what people do (or what people will do). This shortcut could biased theconclusions of researches, in the large domain of persuasion as well as in the morerestricted domain of the persuasive technologies. In conclusion, we would like topromote a theoretical, methodological articulation between HMI and social psychology.