The word "fairness" seems to be everywhere in our political dialogue these days.

Is it fair for Wall Street bankers who were bailed out by taxpayers to go back to paying bonuses as usual? Is it fair that government em­ployees have generous fringe benefit packages when most taxpayers don't enjoy similar benefits? Is it fair to reduce taxes for the wealthy while cutting back teacher salaries, Med­icaid, and child nutrition programs to reduce budget deficits? Is it fair to require everyone to buy health insurance? On the other hand, is it fair to ask others to pay the health expenses of those who don't buy insurance?

Generations of cynics have claimed that the idea of fairness is nothing more than a way of obscuring our naked self-interests. However, the emerging, multidisciplinary science of fairness contradicts them. A sense of fairness is in fact an important part of human nature, "outliers" or the Bernie Madoffs excepted.

Fairness varies, involves compromise

There are so many differences of opinion on the subject because fairness is not a formula or recipe. Our sense of fairness is shaped by various cultural influences, the immediate context, and, of course, the lure of our own self-interests. Consider how long the US tolerated slavery and how many generations it took for women to obtain the right to vote.

At heart, fairness refers to an aspect of our relationships with one another. It means taking into account different, often conflicting, interests and trying to strike a balance. Compromise is an indispensable solvent where fairness issues are concerned. But a compromise may be hard to achieve when there are two sharply opposed fairness claims.

One example is the long-running debate over affirmative action in college admissions. Each side has based its case on merit, and each has a legitimate point.

Three categories of fairness in social contract

What could be called the "deep psychology" of fairness also plays a major part in our social contract – the implicit understanding that binds together any stable and reasonably harmonious society. Our social contract involves three different categories of fairness – equality, equity (or merit), and reciprocity.

The principle of equality is embedded in our basic human rights, from "equal protection of the laws" to "one person, one vote." More important, we are all more or less equal in terms of our basic survival needs. Any society that systematically shortchanges these needs puts its social contract at risk. Think of Egypt and other Middle Eastern oligarchies where uprisings have erupted recently.

Beyond providing for the basic needs of our people, which many studies show has broad public support, the principle of equity is also vitally important to the practice of fairness. Aristotle defined equity as "pro­portionate equality" – rewards that are weighted according to what people "deserve" through the use of their talents, efforts, and achievements. Capitalism, for example, is often touted as an economic system that rewards merit, though there are various distortions of the ideal model in practice.

However, equality and equity are insufficient to uphold the social contract. Fairness must also include reciprocity. Reciprocity puts a counterweight on the scale. It obligates us to pay for the benefits we receive from society. As the great Roman legal scholar Cicero put it, "There is no duty more indispensable than re­turning a kindness." Without reciprocity, a society would devolve into a pattern of "free-loading" and exploitation. Taxes and public service obligations are two of the ways we have devised for closing the loop.

More than political rhetoric

Fairness is an ongoing issue, not just in our individual interactions but also in the very fabric of society. Ab­so­lute fairness, of course, is an un­attainable ideal, but it remains a goal worth striving for. In fact, we are wired for it. As the distinguished biologist Garrett Hardin pointed out, "The first goal of [social] justice is to create a modus vivendi so that life can go on, not only in the next few minutes, but also indefinitely into the future."

Our innate sense of fairness is about more than simply political rhetoric. It's a compass that points us in the right direction.

Peter Corning is the author of "The Fair Society: The Science of Human Na­ture and the Pursuit of Social Justice."