A team built three real doors, put a real goat behind one, and the goat won.
A research team built a physical Monty Hall problem with three doors and real goats. The goats learned the latch and now switch doors every time, winning 66 percent of trials. The team's genuine mathematical breakthrough was mentioned last and briefly.
Researchers at the Halloway Institute for Applied Doubt have built a working Monty Hall problem. Three doors. One prize. Two goats. They ran it 900 times with real people and real goats.
The goats won 66 percent of the time.
"We did not design the study so that goats could win," said Dr. Ines Kabel, who led the work. "There was no winning condition for the goats. They found one."
The classic puzzle is simple. You pick a door. A host opens a different door and shows you a goat. You should switch. Switching wins two times in three.
Kabel's team wanted to know whether people would switch when the goat was standing right there, breathing. People did not. They stayed. They stayed 71 percent of the time.
"The goat looks at them," Kabel said. "They stop doing arithmetic."
The goats began switching
On day four, the team noticed the goats moving between doors during the pause. Nobody opened anything for them. The goats had worked out the latch.
"A goat switched. Then all three goats switched," said Marcus Oyelaran, the lab's animal handler. "They switch every time now. They are correct every time. We are not."
Kabel is careful about what this shows. She stresses the study measured door choice only. It did not measure understanding.
"The goats may not know why switching works," Kabel said. "Neither do the people. The difference is that the goats do it anyway."
The sample size was adequate. It was not. Kabel wants 3,000 trials and a second herd before anyone calls this settled. She expects funding to be difficult.
The same paper contains a second result. The team says it found a general method for solving conditional probability puzzles that has eluded mathematicians for fifty years. It fits on one page. Kabel mentioned it last, and briefly.
"Yes, that part works," she said. "It is not very interesting. The goats are the story."
The institute has now closed the corridor to visitors. Three doors remain installed. The goats are behind them, or somewhere, and the latch has been replaced with a bolt.
"We are not saying the goats understand probability," Kabel said. "We are saying they are behaving as if they do, in a controlled setting, on our equipment, faster than we can write it down. The implications are, frankly, terrifying."
The original puzzle, in its harmless paper form, remains available to the public. Kabel recommends solving it there. She recommends not building it.
