A survey in 2006 by the Pew Research Centre in the United States aroused interest in the ideology-happiness link. In the survey, 45 per cent of Republicans reported being very happy compared to 30 per cent of Democrats.
This result was followed up in three peer-reviewed articles. The first found evidence of the effect with a large sample but failed to report a measure of its magnitude.
In two others, the correlation between ideology and happiness ranged from .08 to .18. In other words, ideology explains at most about 3 per cent of the variation in happiness. Using conventional standards, a researcher in a fit of generosity may label this "small, possibly approaching medium".
In one sense, these small effects are intuitive: of all the factors that might influence your happiness, is ideology really that important?
Let's assume that the ideology-happiness association exists and is worth discussing further. Why might someone with conservative views be happier?
For starters, conservatives tend to be wealthier, more religious and are more likely to be married. Ideology itself may have little to do with happiness: rather, it is these characteristics associated with it that are important.
In this sense, small observed ideology-happiness associations are surprising. If ideology is a proxy for these other variables, shouldn't the ideology-happiness link be stronger?
The original research article proposed several other explanations for the link, but found strongest evidence for system justification. According to this explanation, conservatives are better able to justify current economic, social and political systems and the inequality they entail. They have greater capacity to rationalise the rich-poor divide.
The two subsequent articles, however, found other variables to be better predictors of happiness than system justification, including religiosity, moral attitudes and number of group memberships.
Another explanation for uncertainty over system justification is that each of the six studies measuring system justification in these three articles measured it differently. One study asked for responses to statements like: "Our society should do whatever is necessary to make sure that everyone has an equal opportunity to succeed", and another that: "Group equality should be our ideal".
The former statement is arguably about equality of opportunity and the latter about equality of outcome. Even someone with liberal views may favour providing the disadvantaged with the opportunity for positive outcomes over providing the outcomes themselves. And even a staunch conservative who opposes handouts to the disadvantaged may support greater opportunities for the disadvantaged to succeed.
So whether or not opposition to equality is the reason conservatives are happier may depend on whether we are talking about equality of outcome or opportunity.
No Australian research data on the ideology-happiness link has been published. Might we expect Australia, with its strong tradition of egalitarianism, to be different to other countries? Perhaps not.
In his recently-released book Battlers and Billionaires, Labor MP Andrew Leigh presented data indicating that although Australians generally support greater equality, Labor voters tended to favour redistribution of income more than Coalition voters.
So even in Australia, conservatives are generally more comfortable justifying inequality. But are they are happier as a result? Or are they happier, but for some other reason?
Perhaps Australian conservatives perceive Labor governments as symptoms of "temporary electoral insanity" (to quote former Liberal senator Reg Withers) and are happy knowing that sanity will eventually prevail. And would a Labor victory in next month's election weaken the ideology-happiness link? Perhaps not - research in other countries suggests conservatives are happier than liberals irrespective of who is in power.
Or perhaps it is the case that Australians, with our history of relative political apathy, are more easily able to detach emotional states from political views.
Dan Costa is a lecturer and researcher in psychology at the University of Sydney.
theconversation.edu.au