An experiment was performed to determine whether the use of realistic materials would improve performance in a deceptive reasoning problem. The task involved selecting from a set of envelopes those which, if they were turned over, could violate a given rule. The rule concerned either a realistic relation (‘if a letter is sealed, then it has a 50 lire stamp on it’) or else an arbitrary relation between symbols (‘if a letter has an A on one side, then it has a 3 on the other side’). Twenty-two of the 24 subjects made at least one correct answer with the realistic material but only seven of them did so with the symbolic materials. The verbal formulation of the rule was also varied but yielded only a marginal interaction with the main variable. It is argued that the critical factor is the intrinsic connexion between items rather than their specific nature.