Reversal test

The reversal test is an attempted heuristic to reduce status quo bias.

The reversal test

It was introduced in the context of the bioethics of human enhancement by Nick Bostrom. Given that humans might suffer from irrational status quo bias, how can one distinguish between valid criticisms of proposed increase in some human trait and criticisms merely motivated by resistance to change? The reversal test attempts to do this by asking whether it would be a good thing if the trait was decreased:

"Reversal Test: When a proposal to change a certain parameter is thought to have bad overall consequences, consider a change to the same parameter in the opposite direction. If this is also thought to have bad overall consequences, then the onus is on those who reach these conclusions to explain why our position cannot be improved through changes to this parameter. If they are unable to do so, then we have reason to suspect that they suffer from status quo bias." (p. 644)

Arguing that any change in the trait would make us worse off is equivalent to arguing that we are currently at a local optimum. Since local optima normally form a very small subset of possible states it is reasonable to put the onus on the people arguing against the change.

Double reversal test

A further elaboration on the reversal test is suggested as the double reversal test:

"Double Reversal Test: Suppose it is thought that increasing a certain parameter and decreasing it would both have bad overall consequences. Consider a scenario in which a natural factor threatens to move the parameter in one direction and ask whether it would be good to counterbalance this change by an intervention to preserve the status quo. If so, consider a later time when the naturally occurring factor is about to vanish and ask whether it would be a good idea to intervene to reverse the first intervention. If not, then there is a strong prima facie case for thinking that it would be good to make the first intervention even in the absence of the natural countervailing factor." (p. 673)

In this case the status quo bias is turned against itself, hopefully reducing its impact on the reasoning. It also incorporates possible arguments from evolutionary adaptation, transition costs, risk, and person-affecting morality that might otherwise complicate the simple reversal test.