Survivorship Bias
We tend to focus on things that survived and overlook things that didn't. This can lead to overly optimistic beliefs.Description
Survivorship bias occurs when we develop a skewed view of a situation by concentrating on the people or things that survived. Things that didn't survive lack visibility and are overlooked. A common result of survivorship bias is overly optimistic beliefs. By focusing primarily on the success stories, we fail to fully understand why the "failures" did not survive, often just assuming that it's due to a lack of qualities found in the survivors. Looking for counter examples when deriving patterns from success stories can be a useful exercise in combating survivorship bias.
Examples
We often attribute the success of famous entrepreneurs solely to their behavior and overlook things like luck and timing. By ignoring the failed companies that followed similar approaches, we might be overly optimistic about the likelihood of our own entrepreneurial success.
It's easy to perceive music from the past as being higher quality than contemporary works. Music from the past, however, has gone through a selection process where higher quality works have survived. With contemporary music, we hear the mediocre along with the good.