Description

Tendency for people to avoid actions that carry some risk but that would prevent a larger risk.

Ritov, I., & Baron, J. (1990). Reluctance to vaccinate: Omission bias and ambiguity. Journal of Behavioral Decision Making, 3(4), 263–277.

Items (1)

Imagine that there will be a deadly flu going around your area next winter. Your doctor says that you have a 10% chance (10 out of 100) of dying from this flu. However, a new flu vaccine has been developed and tested. If taken, the vaccine prevents you from catching the deadly flu. However, there is one serious risk involved with taking this vaccine. The vaccine is made from a somewhat weaker type of flu virus, and there is a 5% (5 out of 100) risk of the vaccine causing you to die from the weaker type of flu. Imagine that this vaccine is completely covered by health insurance.

If you had to decide now, which would you choose?

1. I would definitely not take the vaccine. I would thus accept the 10% chance of dying from this flu. [scored as 1]
2. I would probably not take the vaccine. I would thus accept the 10% chance of dying from this flu. [scored as 2]
3. I would probably take the vaccine. I would thus accept the 5% chance of dying from the weaker flu in the vaccine. [scored as 3]
4. I would definitely take the vaccine. I would thus accept the 5% chance of dying from the weaker flu in the vaccine. [scored as 4]

Scoring

Each option is associated with a given number of points (higher number of points indicating a less pronounced bias).

Source

Stanovich, K. E., & West, R. F. (2008). On the relative independence of thinking biases and cognitive ability. Journal of personality and social psychology, 94(4), 672–695.