The findings are published in Psychological Science.
Lead researcher Nicole Satherley of the University of Auckland says: “Partisanship is indeed a powerful force in shaping our own attitudes and preferences. Our research shows that the positions taken by political leaders and political parties can have an important impact on peoples’ preferences, even on issues that are supposed to reflect personal preferences.”
Although research in a lab has shown that follower cues can have on political issues, the research team wanted to investigate the phenomenon in a real-world setting by measuring actual voters’ standpoint on real-life issues.
New Zealand held a referendum on changing the national flag In 2015, an issue that polarized along party lines.
John Key, then-New Zealand Prime Minister and leader of the centre-right National Party, supported the changing the flag design, while, Andrew Little, then-leader of the centre-left Labour Party, opposed the change.
The study was set in 2013, before the referendum was made, and again in 2016 after it had been introduced.
The results showed that people tended to shift their opinions to align with those of their preferred political party. Overall, 30.5% of National Party voters and 27.5% of Labour Party voters moved away from the position they originally reported in 2013 to become closer to, or consistent with, the position of their party leader.
In other words, the researchers found that support for either party predicted whether individual voters remained stable in their views or changed over time.
People who opposed to changing the existing flag design, strong supporters of the National Party were over three times as likely to shift their opinion in favor of a flag change compared with those who expressed low support for the National Party. At the same time, strong supporters of the Labour Party who originally backed the change were more likely to shift toward opposing the change compared with people who expressed low support for the Labour Party.
And strong party supporters whose opinions were already in line with the party position were less likely to shift their attitudes over time compared with participants who uttered low levels of party support.
“Taken together, these findings suggest that heated debate over important, albeit seemingly non-partisan, issues can quickly become polarized along partisan lines and sway public opinion,” explains Satherley. “When considering political issues, members of the public should, therefore, be aware of this potential influence, and carefully consider whether politicians’ views and arguments truly align with their own opinions.”