Putting adjustment sack in the anchoring and adjustment heuristic: Differential processing of self-generated and experimenter-provided anchors

People's estimates of uncertain quantities are commonly influenced by irrel evant values. These anchoring effects were originally explained as insuffic ient adjustment away from an initial anchor value. The existing literature provides little support for the postulated process of adjustment, however, and a consensus that none takes place seems to be emerging. We argue that t his conclusion is premature, and we present evidence that insufficient adju stment produces anchoring effects when tine anchors are self-generated. In Study 1, participants' verbal reports made reference to adjustment only fro m self-generated anchors. In Studies 2 and 3, participants induced to accep t values by nodding their heads gave answers that were closer to an anchor (i.e., they adjusted less) than participants induced to deny values by shak ing their heads-again, only when the anchor was self-generated. These resul ts suggest it is tune to reintroduce anchoring and adjustment as an explana tion for some judgments under uncertainty.