The Availability Heuristic assess the frequency of a

The Availability Heuristic “assess the frequency of a class or the probability of an event by the ease with which instances or occurrences can be brought to mind” (T&K, 74: 1127)

“Availability heuristic” • Events that are easy to imaging • “spring to mind” • are judged to be more frequent • I. e. . , highly vivid, • emotional • can be imagined

Example: Availability bias • Which is more likely cause of death in US? • killed by falling airplane parts? • shark attack

Implications: What more probable (plausible) • Media coverage (crime rate ) • Events easy to image (terrorist attack) • Events/outcome the are difficult to visualize • (interaction effects)

Are easily imagined events judged to be more probable? • • • Carroll (1978) 1976 election Imagine Carter wins or Imagine Ford wins • …predict “Who is likely to win? ”

What if event is extremely negative? • DENIAL • nuclear war • • AIDS Environmental disasters Global “warming “rape of Indian Ocean”

VIVIDNESS • how concrete or imaginable something is • What course to take? • Recommend Not • Condition • Face-to face 4. 73 • visuals • TV • “face-to-face” communications . 50 • No eval • uation 3. 33 1. 39 • Base rate 4. 11 . 94 • (Borgida & Nisbett, 1977)

Legal Significance? (during jury deliberations? ) • Pallid condition: • Vivid version: • “On his way out the door, Sanders (the defendant) staggered against a serving table, knocking a bowl to the floor” • “On his way out the door, Sanders staggered against a serving table, knocking a bowl of guacamole dip to the floor and splattering guacamole on the white shag carpet. ”

Why? Delayed effect • Vivid information easier to remember • Easier to retrieve from memory • “Vivid events may be judged more probable”

TYPE of INFORMATION • Most likely to be remembers……> • more persuasive (delayed effect) • • • Case histories (versus stat abstract) Video (versus written oral presentations) Personal experience “VALID, RELIABLE, TIMELY”

How to use these insights? • Publicize explicit but non-obvious comparisons: • “More people will die from stomach cancer than from car accidents”