Traditionally politics was thought to be an observational, not an experimental, social science. In his 1909 American Political Science Association presidential address Lawrence A. Lowell said ‘we are limited by the impossibility of experiment.’ It took a long time for this view to be over-turned. Today an increasing number of political scientists are running experiments to the extent that experiments are on the verge of becoming mainstream.

Many are attracted to experiments because they help answer causal questions in a satisfactory way. Experiments, when conducted properly, provide a true rather than imagined counterfactual by establishing treatment and control groups. Randomisation ensures subjects are identical in all other regards (observed and unobserved) except for the treatment. This of course is not to overlook the difficulties faced by experiments: it remains true that for many political science phenomena experiments remain impractical and/or unethical to conduct. What political scientists have realised however is that we are not ‘limited by the impossibility of experiment.’

Political trust is one of the most researched areas in political science. Yet little is known about what causes political trust to vary and there exists almost no experimental data on this subject. Nick Faulkner (Monash), Kyle Peyton (Yale) and I were interested in the effect of information on political trust. To this end we ran an experiment designed to examine the causal effect of one of the most commonly cited causes of political trust: political probity. In this experiment subjects were randomly assigned a purported newspaper article that made the argument that a) politicians are, by and large, honest and civic minded, or b) politicians are dishonest and sly.

We found individuals exposed to arguments about politicians being honest and civic minded report higher levels of political trust than individuals exposed to arguments about politicians being dishonest and sly. In doing so we show that political trust is very malleable. When exposed to a single argument about the integrity of politicians, subjects reported levels of trust improve, although we are not sure for how long. The findings, reported in the January 2015 edition of the Australian Journal of Political Science, are (to my knowledge) the first experimental tests of whether probity affects levels of political trust. The results demonstrate that survey measures of political trust aren’t simply another measure of ideology. Instead, they capture the public’s (real or imagined) belief about the honesty of politicians.

A link to the full article can be found here: http://www.tandfonline.com/doi/full/10.1080/10361146.2014.979759