Biases implicit in the availability heuristic affect people's estimates of risk.

Judge as of 2008 against the psychology literature. True: established research shows that the availability heuristic (judging likelihood by how easily examples come to mind) leads to systematic biases in people's risk estimates, such as overestimating vivid or heavily publicised causes of death. Mostly true: the effect is well supported but with caveats about its size or how general it is. Mixed: the findings were substantially disputed as of 2008. Mostly false: the support is narrow or mostly anecdotal and the claim overgeneralises. False: the research shows that availability does not affect risk estimates.

Set before the research began.

1. E1 ERIC - EJ199042 - Judged Frequency of Lethal Events., Journal of Experimental Psychology: Human Learning and Memory, 1978-Nov ERIC (Education Resources Information Center), indexing Journal of Experimental Psychology: Human Learning and Memory · November 1978

   “Subjects tended to overestimate the rate of rare causes, underestimate likely causes, and be influenced by drama or vividness.”

2. E2 People don’t overestimate the frequency of dramatic causes of death Technical University of Munich, Corporate Communications Center

   “However, it was not possible to replicate this result with the data from the more recent studies.”

3. E3 Availability Heuristic In Psychology: Definition & Examples Simply Psychology · 17 September 2026

   “The effect is real and practically meaningful, but the classic demonstrations overstate its typical strength (Weingarten & Hutchinson, 2018).”

4. E4 Availability Heuristic In Psychology: Definition & Examples Simply Psychology · 17 September 2026

   “Tversky and Kahneman introduced availability in a dedicated 1973 paper, then presented it alongside the representativeness and anchoring/adjustment biases in their landmark 1974 Science review on judgment under uncertainty (Tversky & Kahneman, 1973; Tversky & Kahneman, 1974).”

E1, the 1978 Journal of Experimental Psychology study on judged frequency of lethal events, found that people overestimated rare causes of death, underestimated common ones, and were influenced by how dramatic or vivid a cause was. That is a systematic bias in risk estimates linked to availability. E4 confirms the heuristic was set out by Tversky and Kahneman in 1973–1974, so it was established well before 2008. E3's caveat on effect size cites a 2018 source, and E2 reports a failed replication using data from more recent, undated studies; neither shows the findings were substantially disputed as of 2008.