Alzheimer patients in the early stage of the disease were asked to participate in the Dictator game, a game in which each subject has to decide how to allocate a certain amount of money between himself and another person. The game allows the experimenter to view the influence of social norms and preferences on the decision-making process. When the data from the experiment are compared with the results of an identical experiment involving two control groups with similar ages and social background, one group with Mild Cognitive Impairment patients, the other with healthy subjects, it appears that the results from the three groups are statistically undistinguishable. This is an indication that Stage I AD patients are as capable of making decisions involving social norms and preferences as any person of their age, and that whatever brain structures are affected by the disease, they do not include, at this stage, the neural basis of cooperation-enhancing social interactions.