How we change what others think, feel, believe and do
In order to get people to act on a large number, get them first to commit to a small number, even one.
Before asking for a donation to help many people, get targets to think about a single person or situation.
When seeking support for any cause where large numbers are affected, focus first (and perhaps only) on individual cases that support your argument.
A charity seeking donations shows a picture of single child in distress and asks people to give to help this single, named child.
A government seeking to build support for welfare cuts seeks out examples of benefit fraud and makes a big deal about these before presenting their money-saving policy.
Hsee et al (2013) studied a kindergarten site that was seeking donations. All subjects were asked how much they would donate. Some subjects had been asked beforehand a hypothetical question about how much they would donate to one child. These people donated more than those who were only asked after viewing the website.
Hsee et al explain this effect by noting how people are initially scope insensitive and subsequently scope consistent.
Scope insensitivity or 'scope neglect' is a mental bias where people do not fully appreciate the difference between medium and large numbers. In in particular, it seems we have difficulty in making sense of how big large numbers really are. It as if we think in terms of 'one, few, lots'. In this way, the different between a thousand and a million seems not that different to the difference between a million and a billion. Perhaps this is related to the way we encode written numbers. Teachers typically overcome this with physical example, for example 'how many footballs would fit into a football stadium'.
Scope consistency uses the consistency principle in that once we have take some action we seek to act consistently with this in the future rather than face the cognitive dissonance or social disapproval. In the example of donations, this means people will donate more to a large number after they have first decided to donate to a small number (even if this was a 'hypothetical' conversation).
Unit Asking helps address the problem of the 'drop in the ocean' effect, where people asked to help large numbers of other people consider such a donation tiny in comparison with the large numbers who need help, and so donate nothing.
In a reversal effect, it is better to ask for help from a single person than asking for help from a crowd of people.
Hsee, C. K. (1996). The evaluability hypothesis: An explanation for preference reversals between joint and separate evaluations of alternatives. Organizational Behavior and Human Decision Processes, 67, 247–257
Hsee, C.K., Zhang, J., Lu, Z.Y. and Xu, F. (2013). Unit Asking: A Method to Boost Donations and Beyond, Psychological Science, 24, 9,
And the big