Preference reversal (PR) occurs when pairs of lottery gambles are evaluated under two different conditions: to choose the gamble preferred to play and assign minimum selling price to each gamble. The preference order is then reversed from one condition to another: while it receives the lowest selling price, the gamble less risked is preferred in condition of play. Many times replicated, this result is considered as a cognitive bias. Recent research suggests that it could be related only to the procedure used to present the gambles (i.e., the evaluation mode): either by pair (joint evaluation or JE) in condition of play, or one by one (separate evaluation or SE) in the pricing task. Then, by reversing the evaluation mode in each condition, PR should be reversed, as it is shown in this study: although the phenomenon still occurs when subjects evaluate gambles in the classical paradigm, we observe an inversion of PR when they have, on the one hand, to play in SE, and on the other hand, to sell in JE. Furthermore, an analysis not often used in this literature provides new elements, which can attest to the cognitive mechanisms underlying the phenomenon: by recording the online information (self-paced display time paradigm) we show the effect of an anchoring and adjustment process when riskiest gambles are preferred. (C) 2007 Societe francaise de psychologie. Publie par Elsevier Masson SAS. Tous droits reserves.