Early Studies in Parapsychology at Duke

Testing at the Laboratory

Four people seated at table watching dice being emptied out of container.

Undated dice test, University Archives Photograph Collection.

Female participant makes eye contact with smiling man holding paper and pointing to cards with symbols on them.

Undated Zener test, University Archives Photograph Collection.

Two children sit at a table opposite each other, drawing, while a smiling woman observes.

Undated test with children, University Archives Photograph Collection.

This page shows a small survey of the kinds of testing done at the laboratory. Testing isn't as easy as it might seem, however. What is the probability that someone can guess the outcome of a dice roll? Or what's printed on a card? What kinds of environmental or previous knowledge can a participant bring in that would influence the results of testing? What effect does mood have on a participant's results?

To navigate these difficulties, researchers developed questionnaires about participant moods and attitudes before testing, and also attempted to build in as many fail safes as possible into the method. 

In many photographs of tests, for example, you will see a black screen separating researchers and participants. Some other times, physical distancing is used, as shown in the first image on this page. Other times there would be multiple researchers with a subject. All researchers kept meticulous notes on all facets of testing and these notes remark on a participant's level of skepticism, mood, fatigue, information on ambient noise in the room, and more.

Some tests, like tests with Zener cards shown in the photos, urge participants to try to discern information they would have no way of knowing. Others, like the drawing exercises shown to the right, encourage participants to try to connect on a psychic level with another person to accomplish a task. Using the photo as an example, these participants are trying to produce the same image(s) without being able to see what the other person is doing.

Female participant and male researcher sit at table in front of rectangular testing machine.

Undated test with machine, University Archives Photograph Collection.

Three testing machines of various sizes sit on a table and floor.

Machines at the laboratory, University Archives Photograph Collection.

Still other tests experimented with technology as a way to eliminate human error. Given its place at Duke, the laboratory had access to engineering and physics faculty and researchers who helped develop a variety of machines to facilitate testing.

A human may accidentally give some indication of which card is being held up next, for example, but a machine probably won't. With a machine like the one shown, the participant would attempt to intuit the next color of light that would be generated- just like they would with Zener cards except without the possibility of human error. The use of increasingly sophisticated machines in testing continues at the Rhine Research Center today.

Buildings on a college campus. The caption reads, "Pure clairvoyance. Mr. Pratt handled (did not look at) cards at B, afterwards at A, Mr. Pearce got his surprising results at C. Both made independent sealed reports to me."

Distance clairvoyance test, University Archives Photograph Collection.

This image shows a clairvoyance test spanning Duke's campus. The caption reads, "Pure clairvoyance. Mr. Pratt handled (did not look at) cards at B, afterwards at A, Mr. Pearce got his surprising results at C. Both made independent sealed reports to me."

One challenge of working with the materials in the collection can be pairing images like this one which describe a method with their reported results. But, alone, they can pave the way for anyone to attempt these experiments themselves. If you give it a try and have some time to dig through the collection, perhaps you can compare your own results with the results of the researchers.

Testing at the Laboratory