But I know you know that I know . . .

Your boss is in today, but he has a nasty case of the flu. What’s more, you heard in the corridors this morning that his supervisor is on the warpath. And everyone knows that his life outside the office hasn’t been great recently. He’s been on the phone all morning and rumor has it that his teenage daughter is in some kind of trouble.

It’s probably not the best time to ask for that raise.

I know, you could probably have figured that one out on your own. But why is it so obvious? After all, it’s not rational for your boss to take his travails out on you. You didn’t do anything wrong. Yet we are all constantly making social calculations and gauging others’ moods in order to guide our own choices, and we assume a certain measure of irrationality in others when we do this. If we are hoping for generosity of spirit from a boss—or a parent or a husband or anyone else for that matter—it makes intuitive sense to wait for a sunny day.

But let’s make it more complicated, like real life. What if your boss knows you are making that calculation? What if he knows that you know that he just won the lottery and fell in love? Say he overheard his secretary telling you. Will he still be an easy touch? Or will he redouble his irrationality, treating you unfairly just to avoid being duped?

Two Berkeley psychologists decided to test this particular brand of irrationality in the laboratory. Eduardo Andrade and Teck-Hua Ho used a modified version of what’s called the “ultimatum game”: In this well-known psychological experiment, volunteers are told that they have a pot of money that they must divvy up for themselves and a stranger. They have two choices: They can choose to divide the money evenly, 50-50, or to keep the lion’s share, 75 percent, for themselves. Those on the receiving end in turn decide the size of the pot, so those with the money know there may be a quid pro quo.

The idea is to see what emotional calculations make people act either fairly or selfishly. So before they actually played the game, the psychologists manipulated the volunteers emotions in this way: Those with the cash were told that the strangers had just seen a film. Some were told that they had seen a sitcom, and were in a fun mood as a result; others were told that a provocative film had left the viewers feeling angry.

The researchers thought the volunteers would more likely be stingy if they thought they were dealing with a happy person than if they expected someone angry. They would in effect calculate that they could get away with a self-centered act because the strangers’ perceived happiness would have them in a generous mood. That’s the laboratory equivalent of picking a good time to ask for a raise.

And this is exactly what happened. As reported in the August issue of Psychological Science, the money handlers were very strategic in their behavior, gauging the strangers’ moods and acting accordingly. However—and here’s the perverse part—this strategic thinking completely evaporated when those with the money knew that the strangers knew in advance about their mood. In that situation, the money handlers did not try to get away with anything. They knew intuitively that their manipulation would be transparent—and ineffective.

These two psychologists work in Berkeley’s business school, and their findings have obvious implications for high-stakes negotiations in the corporate world and in international diplomacy. But for most of us the stakes seem pretty high even in our own families and workplaces, where the same psychological lessons and insights apply. It may surprise some to know just how manipulative we are in the first place, when we think we can get away with it.

For more insights into the quirks of human nature, visit “We’re Only Human . . .”