The power of graphs in political communication

Communicators who manipulate graphs can motivate people to take action (or inaction), particularly when it aligns with their biases.

In a recent study of 540 people (Hughes, 2015), representative of the US population in gender, education, age and ethnicity researchers found that republican supporters were 40 per cent less likely to support government action to address income inequality if they were shown the top graph instead the bottom one (along with a consistent text-based description of the issue).

Regardless of how the text characterised the information, the graph had a dramatic effect on Republican voters.

This technique uses the ability of using graphs to clearly communicate a message to people combined with exploiting a powerful confirmation bias to achieve a desired political outcome.


The study looked at how graphs can be used to persuade people's motivation to take action on political issues. The authors noted that almost all political communication studies had focused on verbal or text based mediums, rather than images or graphs.

It should be noted here that altering the scale of graphs to suit your argument verges on manipulation, as opposed to persuasion. In political communication this is often used as a way way to trick the message recipient into changing their mind or take a particular action, such as voting for certain political party or donating money to it.

While it is unlikely that this technique would be able to persuade partisan voters to change sides it could be used effectively to motivate supporters to contribute more money or effort to their chosen party, in addition to supporting greater government action to address their policy concerns.


  • Hughes, A. G., 2015. Visualizing inequality: How graphical emphasis shapes public opinion. Research and Politics, pp. 1-5.