Cynicism comes at a price. Literally.

That’s the conclusion of newly published research, which finds holding cynical beliefs about humanity is harmful not only to your personal health, but also to your personal wealth.

University of Cologne researchers Olga Stavrova and Daniel Ehlebracht report cynics in both Germany and the United States make less money in the long run than optimists. The only exceptions to this rule, apparently, are societies where holding a cynical attitude is the rule rather than the exception.

Under most circumstances, they write, ''overcoming cynical beliefs and building faith in humanity can help us enhance our financial well-being by reaping the fruits of mutual cooperation and joint efforts.''

In the Journal of Personality and Social Psychology, Stavrova and Ehlebracht describe five studies that back up this thesis. The first utilizes data on 1,146 participants in the Americans' Changing Lives survey who were surveyed in 2002 and again in 2011.

Their degree of cynicism was measured by their level of agreement (or disagreement) with such statements as ''Most people will use somewhat unfair means to gain profit or an advantage.'' They also listed their own and their spouse's joint income.

The second study used data on 497 participants in the General Social Survey. They responded to a similar set of statements in 2010 and again in 2012.

The results were strikingly similar. Both years they were surveyed, cynics had lower incomes than optimists. In addition, the researchers found a link between cynicism expressed in the first survey and income in the second, with optimists out-earning their cynical counterparts.

A third study featured 15,698 Germans who were surveyed annually between 2003 and 2012. The researchers found participants' ''baseline levels of cynicism'' affected their earnings trajectory over the next decade.

Specifically, the monthly income of the least cynical people increased by about 230 Euros (approximately $250) over nine years, while the most cynical people ''did not experience any significant income increase at all over that period of time.''

The researchers caution that this equation does not apply to all societies. In nations with high homicide rates, low levels of charitable giving, and an overall high level of ''societal cynicism,'' cynics earn as much as their less-cynical counterparts. In those parts of the world where a dog-eat-dog mentality reigns, cynicism apparently is warranted — although, even in such places, it did not provide any financial advantage.

So, unless you're living in one of those societies (such as Russia), ''cynical beliefs about human nature have adverse effects on individuals' income,'' the researchers conclude.

''Although cynical individuals were more likely to report worse health and lower education, these differences could not completely explain their lower earnings,'' they write. Nor, it turns out, could the fact cynics ''were more likely to be more neurotic and introverted.''

After ruling those factors out, Stavrova and Ehlebracht came up with a more subtle explanation for their findings.

''Cynical individuals are likely to lack the ability (or willingness) to rely on others, and therefore face serious impairments in regard to living and working in a social world,'' they write. ''They are likely to suspect mean motives behind other people's behavior, might be less likely to join collaborative efforts and avoid asking for help in case of need.''

These tendencies, they add, ''may eventually undermine their economic success.''

Cynicism is, of course, easy to fall into, especially for those who follow the news. But be aware that such a disposition colors many aspects of your life, including your finances.

Rewards generally require taking risks, and you're not likely to do so if you're convinced the game is rigged.

Pacific Standard grapples with the nation's biggest issues by illuminating why we do what we do. For more on the science of society, sign up for its weekly email update or subscribe to its bimonthly print magazine.