Psychological inoculation decays without periodic recall-based boosters

Evidence

In the final experiment, we kept everything identical to the first experiment with one crucial change: we only followed up with people at the end of the two-month testing period. This time we found what we had anticipated: although there was still improvement in people’s ability to spot fake news if they were exposed to the Bad News intervention (versus the control group), after nine weeks there was significant decay of the effect compared to baseline. In fact, a majority (64 per cent) of the effect appeared to have decayed after two months. What happened was that unbeknownst to us, we were inadvertently ‘boosting’ people’s immune responses by repeatedly reminding and engaging them with the issue of misinformation in the first experiment. — Sander van der Linden, Foolproof, 813

Categorization

• DEEPTHINKING: A clean methodological lesson: the booster effect was hiding inside the measurement design, and only removing weekly repetition revealed the true decay curve — a distillation of why testing frequency itself shapes the effect being measured.
• XREF: Directly grounds and pays off chapter 11’s claim that inoculation ‘can work therapeutically’ — here shown as a function of periodic re-exposure. — connects to: Pre-exposing people to weakened persuasive attacks cultivates mental resistance against later misinformation. — Sander van der Linden, Foolproof: Why Misinformation Infects…, 633
• recurring: this claim recurs 2 times within its source