Random idea.

Suppose you invent a head-dress (could be a cap, hat or visor) which contains a patch that measures skin-conductance. The head dress would display the scaled skin-conductance graph of the wearer. This would allow other people would know how stressed you are, and to a certain extent, whether you are lying. However, the display for the skin-conductance is designed such that you can only read the skin-conductance of other people if you are wearing a particular kind of goggles.

Experiment one.

1. Get a bunch of people. Give half of them special goggles.

2. Split them into pairs, so that 1/3 of the pairs have 2 goggles, 1/3 of the pairs have one, and1/3 of the pairs have none.

3. The researcher, while wearing the special goggles, observes them having a conversation with each other, with perhaps some prompting questions.

Which of the cases is the most stressful? Both partners having goggles? Both without goggles? Being the only one without goggles? Or being the only one with goggles?

Experiment two. (Same thing, except the bolded parts)

1. Get a bunch of people. Give half of them special goggles, and give the other half of them similar-looking but normal goggles.

2. Split them into pairs, so that 1/3 of the pairs have 2 special goggles, 1/3 of the pairs have one, and1/3 of the pairs have none.

3. The researcher, while wearing the special goggles, observes them having a conversation with each other, with perhaps some prompting questions.

Which of the cases is the most stressful? Both partners having special goggles? Both without special goggles? Being the only one without special goggles? Or being the only one with special goggles? Would they be able to tell if their partners have special goggles?