Who Hit Harder?

From the back seat: “She hit me harder!” “I did not. He hit me harder first.”

Usha, driving, tells them both to stop. Her husband says they get it from her side of the family.

At eleven that night the two adults are in the kitchen. “All I said was that you might have rung. And you went for me.” “I went for you? After the way you said it?”

All four of them are telling the truth.

Two eyes for an eye

In 2003 a group of researchers ran an experiment that Andy Clark describes in Surfing Uncertainty. A small device pressed down on a volunteer’s left forefinger. The volunteer then had to reproduce exactly that pressure, using the right forefinger to push on the left.

They could not. Time after time they pressed too hard. The researchers put a figure on it. When a force is one you produce yourself, you feel it as about half as strong as the same force applied by something else. They called the paper “Two Eyes for an Eye”.

When the volunteers matched the pressure by moving a joystick, so that their own finger was not doing the pressing, they were much more accurate.

Why you cannot tickle yourself

The explanation Clark gives is the one that accounts for tickling. Your brain predicts the sensations your own movements are about to cause, and it turns those sensations down. A tickle needs surprise, and you cannot surprise yourself. He compares it to telling yourself a joke. However good it is, you already know the punchline.

The proof is rather sweet. In another study, people tickled their own palms through a robot arm. When the robot added a slight delay or changed the angle, the touch began to tickle. The brain’s forecast no longer matched, so the feeling came through at full strength.

The step-ladder

Now put two people together. Clark’s example is the playground. One child gives a shove. The other returns what he felt, as he felt it. But he feels his own shove at half strength, so what he sends back is larger than what arrived. The first child receives that in full and matches it, by her own muted measure. The exchange climbs like a ladder.

Afterwards each child swears that the other hit harder. Clark’s point is that both are reporting their sensations truthfully.

From shoves to sentences

The experiment was about fingers. Clark adds only that the same could hold for other kinds of physical exchange. So the next thought is mine and it is not proven.

I think something similar happens with words. I know what I meant by my own remark. I know I was tired, and that I softened it at the last moment, and that I was partly joking. It reaches you with none of that attached. Your reply reaches me the same way, stripped of everything you know about why you said it.

If that is right, a couple who each try to give back exactly what they got will escalate without either of them choosing to. Each will be sincere in saying, “You started it.”

Aim low

The joystick suggests a remedy. The volunteers did better when they stopped trusting the feel of their own finger and used an outside measure.

In a quarrel, the outside measure is the other person’s face. Since you cannot feel your own sentence land, you can ask how it landed. And you can aim to return less than you believe you received, on the assumption that your gauge reads low.

None of this excuses anyone. It only explains how two fair-minded people can each end the evening feeling like the injured party.

This is about ordinary quarrels between equals. It is not about violence. If someone is hitting or threatening you, that is not a trick of perception, and you should contact the police or a domestic violence service near you.