Availability Bias
Availability bias is the tendency to overweight information that comes to mind easily — usually because it's recent, vivid, or emotionally charged. If you can quickly recall an example, your brain treats it as common.
Examples
- Fear of flying: Plane crashes are dramatic and heavily covered, so people overestimate the risk of flying relative to driving, which is statistically far more dangerous.
- Investing: A recent market crash looms large in memory, causing investors to be overly cautious long after conditions have changed. Conversely, a recent boom makes risks feel distant.
- Hiring: A manager who just had a bad experience with a remote worker may overestimate the risks of remote work, ignoring the Base Rates of remote employee performance.
Connections
Availability bias distorts Probabilistic Thinking by substituting "how easily can I recall this?" for "how often does this actually happen?" The cure is to look up Base Rates rather than trusting your memory's sense of frequency.
Map is Not the Territory applies here too: your mental map of what's common is shaped by what's memorable, not by what's representative. The map of risks you carry in your head is warped by the evening news.
See also: Cognitive Biases for the broader landscape of systematic reasoning errors.