Most of us, whether we admit it or not, are moral hypocrites. We judge others more severely than we judge ourselves.

Mounting evidence suggests moral decisions result from the jousting between our knee-jerk responses (think "survival instinct") and our slower, but more collected evaluations. Which is more responsible for our self-leniency?

To find out, a recent study presented people with two tasks. One was described as tedious and time-consuming; the other, easy and brief. The subjects were asked to assign each task to either themselves or the next participant. They could do this independently or defer to a computer, which would assign the tasks randomly.

Eighty-five percent of 42 subjects passed up the computer’s objectivity and assigned themselves the short task – leaving the laborious one to someone else. Furthermore, they thought their decision was fair. However, when 43 other subjects watched strangers make the same decision, they thought it unjust.

Time to think

The researchers then "constrained cognition" by asking subjects to memorize long strings of numbers. In this greatly distracted state, subjects became impartial. They thought their own transgressions were just as terrible as those of others.

This suggests that we are intuitively moral beings, but "when we are given time to think about it, we construct arguments about why what we did wasn’t that bad," said lead researcher Piercarlo Valdesolo, who conducted this study at Northeastern University and is now a professor at Amherst College.

The study, funded by the university, will be detailed in an upcoming issue of the Journal of Experimental Social Psychology.

The researchers speculate that instinctive morality results from evolutionary selection for team players. Being fair, they point out, strengthens mutually beneficial relationships and improves our chances for survival.

Loathe to admit

So why do we choose to judge ourselves so leniently?

We have a lot wrapped up in preserving a positive self-image, said Valdesolo, and thus are loathe to admit, even to ourselves, that we sometimes behave immorally.

A flattering self-image is correlated with rewards, such as emotional stability, increased motivation and perseverance. "It is a very functional part of our psychology … but it is not always a desirable one," explained Valdesolo.

Since, in real life, we can’t drive everyone into a state of pronounced distraction, he continued, the hard part is figuring out how moral instincts may be better harnessed.

When asked if this meant ubiquitous Blackberries and iPods may make society more just, Valdesolo said, laughing, "our research suggests it."