Seeing a new use for drinking water

Introduction: Solving a problem sometimes means using an everyday object in an unusual way. Researchers tested whether presenting an object in its ordinary role makes it harder for people to think of a new use for it.

Participants: Eighty-four adults aged 19 to 63 (mean age = 34; 47 women, 36 men and 1 nonbinary person) were recruited at a public library in Melbourne, Australia, and received a $10 book voucher. Most (71%) had been born in Australia; the rest had been born in 14 other countries. People who said they had seen the puzzle before were not included.

Method: Participants gave written informed consent and were told they could stop at any time. Each was tested alone. A clear plastic tube, 40 cm tall and too narrow for a hand, was fixed upright to a table, with a table-tennis ball resting at the bottom. The participant's task was to get the ball out without tipping or damaging the tube. The only workable solution was to pour water into the tube so that the ball floated to the top. Participants were randomly assigned to one of two conditions (42 per condition).

Neutral condition: A plastic jug of water sat on the table among the other items available for the task (a pencil, a ruler, string, tape and a paper clip).

Drinking-water condition: The same items were on the table, but the water was in a drinking glass on a small tray with a napkin and a cookie, placed next to the participant. The researcher said, "Here's a glass of water and a snack for you while you work."

The researcher, who sat behind a screen, recorded the time in seconds from the start of the task until the participant began pouring water into the tube. Participants who had not solved the puzzle after 10 minutes were stopped and given a time of 600 seconds. Afterward, the researcher showed every participant the solution, explained the purpose of the study, and recorded no names with the data.

Results and Discussion: The table shows the results. The difference between the conditions in the percentage of participants who solved the puzzle was statistically significant. Many participants in the drinking-water condition said afterward that they had not thought of the water as one of the tools.