Mirroring Intentional Forgetting in a Shared-Goal Learning Situation

Background: Intentional forgetting refers to the surprising phenomenon that we can forget previously successfully encoded memories if we are instructed to do so. Here, we show that participants cannot only intentionally forget episodic memories but they can also mirror the forgetting performance of an observed model. Methodology/Principal Findings: In four experiments a participant observed a model who took part in a memory experiment. In Experiment 1 and 2 observers saw a movie about the experiment, whereas in Experiment 3 and 4 the observers and the models took part together in a real laboratory experiment. The observed memory experiment was a directed forgetting experiment where the models learned two lists of items and were instructed either to forget or to remember the first list. In Experiment 1 and 3 observers were instructed to simply observe the experiment (simple observation instruction). In Experiment 2 and 4, observers received instructions aimed to induce the same learning goal for the observers and the models (observation with goal-sharing instruction). A directed forgetting effect (the reliably lower recall of to-be-forgotten items) emerged only when models received the observation with goal-sharing instruction (P<.001 in Experiment 2, and P<.05 in Experiment 4), and it was absent when observers received the simple observation instruction (P>.1 in Experiment 1 and 3). Conclusion: If people observe another person with the same intention to learn, and see that this person is instructed to forget previously studied information, then they will produce the same intentional forgetting effect as the person they observed. This seems to be a an important aspect of human learning: if we can understand the goal of an observed person and this is in line with our behavioural goals then our learning performance will mirror the learning performance of the model.