PEAR (Princeton Engineering Anomalies Research)

An icebreaker

For nearly three decades, a Princeton engineering lab ran millions of trials testing whether human intention could subtly influence random machines. It reported tiny statistical effects; a three-lab replication failed to reproduce them, and the lab closed in 2007.

Ask one of these · tap to take it

Could intention leave a measurable trace on pure randomness?
How small an effect still counts as real?
What separates a rigorous experiment from a flawed one?
Why do some results only appear across huge sample sizes?

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Worth knowing · 1 of 5

What did the lab actually test?

Researchers asked volunteers to try mentally influencing machines generating random outputs, running millions of trials over nearly three decades. They also studied whether people could describe distant, unseen locations.

Worth knowing · 2 of 5

What did the lab report finding?

It reported a very small statistical deviation from chance across its combined trials, describing the effect as consistent though tiny. The founder argued this small, repeated deviation was itself meaningful evidence.

Worth knowing · 3 of 5

What was the strongest criticism of the results?

Critics argued that across millions of trials even minute biases in equipment or analysis could produce an apparent effect. A replication run across three labs, including this one, failed to reproduce the original result, and most physicists never accepted it.

Worth knowing · 4 of 5

Why did the university let it continue so long?

The lab operated for nearly thirty years under its founder's standing as a respected engineering dean, despite ongoing discomfort from colleagues who saw it as an embarrassment. Princeton itself never formally endorsed its conclusions.

Worth knowing · 5 of 5

What happened to the research after the lab closed?

The lab closed in 2007, and its founder and lab manager moved its equipment and data into a separate nonprofit to continue similar work. That successor organization still operates today, apart from the university.

Words to know

Random event generator (REG)An electronic device producing random binary outputs, the main tool used to test claimed mental influence.

PsychokinesisThe hypothesized ability of the mind to physically affect matter without direct physical contact.

Remote viewingA claimed ability to describe a distant or hidden location using only the mind.

More words

Meta-analysisA statistical method combining results from many separate studies to look for an overall pattern.

Effect sizeA measure of how large a result is, distinct from whether it is statistically significant at all.

A voice · 1 of 3

Robert Jahn · Engineering dean who founded the lab

He founded the lab in 1979 while dean of Princeton's engineering school, and co-authored a 1987 book with the lab's manager summarizing nearly a decade of experiments as, in his view, statistically meaningful.

A voice · 2 of 3

Brenda Dunne · Developmental psychologist who managed the lab

She managed day-to-day operations for the lab's entire run, co-authoring its central findings and later helping transfer its data and mission into a successor nonprofit after the lab's 2007 closure.

A voice · 3 of 3

Robert Park · Physicist who publicly criticized the lab

In Voodoo Science (2000) he cited the lab among his examples of research whose tiny effects never grew clearer as methods improved, a pattern he treated as a warning sign.

A line to leave them with

Millions of trials, a tiny number, and a debate that outlasted the lab.