The Hawthorne Effect

Summary

More or Less – "The Hawthorne Effect"

Podcast: More or Less
Host: Tim Harford
Guest: John List (Professor of Economics, University of Chicago)
Date: October 12, 2013
Episode Theme:
A deep dive into the legendary Hawthorne Effect: what really happened at the Hawthorne plant in 1920s Chicago, the origins and interpretations of the phenomenon, and the modern-day myth-busting research that reveals the true story behind one of social science’s most cited studies.

---

Episode Overview

This episode explores the myth and reality of the Hawthorne Effect, a concept born from a 1920s experiment at the Hawthorne plant in Chicago, which claimed that workers' productivity increased simply because they were being observed and received attention. Tim Harford guides listeners through the history, widely-held misconceptions, and the rediscovery of original research data that illuminate what really happened.

---

Key Discussion Points & Insights

1. The Hawthorne Plant Experiment: Origins and Legend

[00:19–02:19]

• The National Academy of Sciences originally set out to determine if lighting affected factory workers’ productivity.
• Regardless of changes—brighter lights, dimmer lights, longer or shorter work breaks, altered workdays—productivity seemed to always go up.
• The apparent cause: not the physical changes in the work environment, but the fact that the workers were being closely observed and receiving attention from experimenters.

Notable Moment:
An original Hawthorne worker recalls how being part of the experiment was a welcome change from monotonous factory routine:

"We liked it. All of us liked it. You know, every day we had to do something different. It wasn't the same thing over and over."
Original Hawthorne Worker, [02:11]

2. The Human Side of Work

[02:19–03:01]

• The grand conclusion: Attention and supervision lifted morale, not the experimental conditions themselves.
• A researcher states:

“We could more logically attribute the increase in efficiency to a betterment of morale than to any of the alterations made in the course of the experiment…”
Researcher from National Academy of Sciences, [02:26]

• This realization gave birth to the concept of the "Hawthorne Effect"—that humans respond to attention, not just incentives or physical conditions.

3. Scientific vs. Managerial Legacy

[03:01–04:49]

• For social scientists: The Hawthorne effect became a complication—an uncontrollable variable that might distort results anytime people are studied.
  • John List:

  "The Hawthorne studies showed that once experimenters show up and start fussing around, they can easily change people's behaviour and spoil the validity of the experiment."
  [03:20]

• For managers: The takeaway was positive—a guide toward higher productivity via better relationships and communication with staff.
  • John List:

  "The Hawthorne experiments showed that that indeed was not correct and that employee relations is extremely important."
  [04:06]

4. The Data Dilemma & Rediscovery

[04:49–06:15]

• John List and Steve Levitt find that the original conclusions were based on qualitative reports—the underlying data was missing for decades. The story was accepted widely despite the lack of concrete evidence.
  • John List:

  "What I found in these early studies is that they never presented data. It was simply a qualitative account that led to these very, very strong statements about how productivity changed, regardless if we made the condition better or worse."
  [04:54]

• A breakthrough came when List found a footnote in a 1970s paper referencing archived microfilms, eventually recovering the original data.

5. Breaking the Myth: What the Data Really Shows

[06:15–07:09]

• The data revealed: Changes in productivity were tied to workers’ days off (Sundays), not to the experimental interventions. After controlling for higher Monday productivity (workers more rested), the famous “Hawthorne Effect” disappeared in the original studies.
  • John List:

  "When you look at the productivity of workers over the week, what happens is that on Mondays they're very, very productive, probably because they're rested from their day off, and by the time they get to Saturday they end up not working as hard as they do on Mondays and Tuesdays. So the empirical fact is, after you control for just that... the entire Hawthorne Effect result disappears."
  [06:15]

6. Do Hawthorne Effects Exist?

[07:09–07:46]

• Despite the original study's debunked results, decades of evidence suggest that being observed or paid attention to can indeed change behavior.
  • John List:

  "I do believe in Hawthorne effects, even though it's not in the original data. I think it's fair to say that decades and decades of research since has taught us the power of receiving attention or people observing us."
  [07:27]

---

Notable Quotes

• “Factory work was tedious and repetitive. Being experimented on was much more interesting.”
  Tim Harford, [01:41]
• "Not only communicating to, but communicating with your employees."
  John List, [04:44]

---

Timestamps for Key Segments

• Opening and Introduction to Hawthorne Study: [00:19–02:19]
• Worker and Researcher Reflections: [02:11–02:46]
• Interpretations for Science and Management: [03:01–04:49]
• Data Search and Rediscovery: [04:49–06:15]
• The Real Findings and Implications: [06:15–07:46]

---

Episode Tone and Style

Tim Harford’s approach is friendly, slightly whimsical, and analytical—demystifying well-worn myths through clear storytelling and sharp skepticism. John List contributes with candor and curiosity, emphasizing both the need for rigorous data and a nuanced understanding of human behavior.

---

Conclusion

This episode debunks an iconic social science finding, underscoring the importance of critical thinking and data integrity. While the original “Hawthorne Effect” is exposed as a myth—at least in the context of its namesake studies—the broader idea that people respond to being observed survives, shaping both experimentation practices and workplace management theory today.

Transcript

[BBC Announcer]

Thank you for downloading from the BBC. For details of our complete range of podcasts and our terms of use, go to bbcworldserveys.com podcasts

[Hannah Barnes]

this is the short edition of More or Less, first broadcast on the BBC World Service.

[Tim Harford]

Hello and welcome to More or Less on the BBC World Service. We're the programme about the numbers which surround us in the news and. And in life. And I'm Tim Harford. This week I thought I'd tell a story, a story about one of the most famous and most misunderstood social experiments in the 20th century. So, are you sitting comfortably? Then I'll begin. We're in 1920s Chicago, one of the great American cities and a major new industrial center. The Hawthorne plant in the suburb of Cicero was making telecommunications equipment and it became the venue for one of the most famous experiments in industrial history. The National Academy of Sciences began an experiment to see how the level of lighting affected how productive workers were. The findings from this simple experiment have become legendary because when fancy new lights were installed, the workers worked harder. And when the lights were removed again, the workers worked harder. Nine more years of research followed and the same results. Lengthened work breaks, the workers worked harder. Shortened work breaks, the workers worked harder. Shorten the working day, the workers worked harder. Lengthen the working day, the workers worked harder. And perhaps that's not a surprise. Factory work was tedious and repetitive. Being experimented on was much more interesting.

[Original Hawthorne Worker]

When they asked me would I like to work in a test room, I thought it was going to be something different than what they were doing.

[Tim Harford]

Here's one of the original workers from Hawthorne being interviewed on an AT&T documentary the year they discovered People years later.

[Original Hawthorne Worker]

We liked it. All of us liked it. You know, every day we had to do something different. It wasn't the same thing over and over.

[Tim Harford]

The grand conclusion was that it wasn't the details of the work environment that mattered. It was receiving close attention from the experimenters.

[Researcher from National Academy of Sciences]

We could more logically attribute the increase in efficiency to a betterment of morale than to any of the alterations made in the course of the experiment. We concluded that the same relationship might exist throughout the plant and that the best way to improve morale was through improved strength supervision.

[Tim Harford]

It was an extraordinary realization. Workers weren't just flesh and blood robots on the production line. They were humans and they responded to attention and to communication. This became known as the Hawthorne Effect.

[John List]

This was not only a very important scientific moment that some researchers would argue is a breakthrough as important as Galileo, but it also had an important effect on industrial relations and how employers actually treat employees.

[Tim Harford]

This is John List, a professor of economics at the University of Chicago, and he's alluding to the fact that there were really two audiences for the Hawthorne effect and it came to mean different things to these two groups of people. For social scientists like John List, the Hawthorne effect was a headache. John List specializes in field experiments, that is, experiments performed on people in their workplace or some other everyday environment. The Hawthorne studies showed that once experimenters show up and start fussing around, they can easily change people's behaviour and spoil the validity of the experiment. But the other group of interested people were management experts, and for them, the Hawthorne studies weren't a headache, but an opportunity to improve productivity.

[John List]

This was a time when people viewed the employee as an automaton, a person who you could turn on and off and they would work Monday through Saturday and have one day off on Sunday. Now, the Hawthorne experiments showed that that indeed was not correct and that employee relations is extremely important.

[Tim Harford]

And you can still see the effects of these experiments today with even just a cursory surf through the management Guru section of YouTube.

[Hannah Barnes]

This study gave rise to the human relations movement, which really shows the importance

[John List]

of not only communicating to, but communicating with your employees.

[Tim Harford]

And that's the story of the Hawthorne studies. And that's where the story ends.

[John List]

You know, that's actually, for me, where the story begins. What I found in these early studies is that they never presented data. It was simply a qualitative account that led to these very, very strong statements about how productivity changed, regardless if we made the condition better or worse.

[Tim Harford]

So John List thought he'd track down the data to see if more lessons could be learned from this seminal research. He searched through academic journal after academic journal. So did his colleague Steve Levitt, most famous as the co author of Freakonomics. But all reports were that the data had been lost. It looked like Levitt and List would have to give up until John List reached for a paper written in the 1970s and blew the dust off a footnote.

[John List]

When I first read that passage, I had to read that sentence in that appendix, I think, 20 or 30 times, because I could not believe that those data could actually exist.

[Tim Harford]

The footnote led Levitt and List to a microfilm archive at the University of Wisconsin, Milwaukee. And after a search there and elsewhere, they uncovered the data from the very first illumination experiments at Hawthorne. And the amazement didn't end there.

[John List]

What we found was something astonishing. When they ran these experiments, they made the experimental change on Sundays. Now they made the experimental change on Sundays because that was the day off for all of the workers in the plant. But when you look at the productivity of workers over the week, what happens is that on Mondays they're very, very productive, probably because they're rested from their day off and by the time they get to Saturday they end up not working as hard as they do on Mondays and Tuesdays. So the empirical fact is after you control for just that, people work harder on Mondays, the entire Hawthorne Effect result disappears.

[Tim Harford]

A legend slain in some ways this is a historical curiosity. There was no Hawthorne Effect in the Hawthorne illumination studies. But sexual scientists remain convinced that being experimented on does change our behavior, and nobody's more convinced of that than John List.

[John List]

I do believe in Hawthorne effects, even though it's not in the original data. I think it's fair to say that decades and decades of research since has taught us the power of receiving attention or people observing us.

[Tim Harford]

John List, economist and co author of a new book, the Y Axis and Just Time for a rummage through the More or less Post bag with Hannah

[Hannah Barnes]

Barnes hi Tim, Our item on left handers a few weeks ago prompted several people to email about this statement From Professor Chris McManus from University College London.

[Tim Harford]

Actually the left handers had fewer children in the 19th century and the result of that was that the genes which make people left handed became less frequent, so fewer left handers were born.

[Hannah Barnes]

Adrian, Tina, Nicola and Eric all wanted to know why, especially as Chris had said in the interview that people at that time tried to hide their left handedness. Well, we got in touch with Chris who told us that the data they have on left handed parents is pretty good and comes from a survey of students in the US born in the late 1800s. As for why they might be having fewer children, he's not sure, but he thinks it may be because left handers got married later because of the stigma and had less time to procreate. And he says although some people tried to hide their left handedness, this would have been difficult in the tight knit communities of the 19th century.

[Tim Harford]

Thank you Hannah. If there are any numbers you'd like us to take a closer look at, do please email us. Our address is moreorlessbc.co.uk and you can also sign up for a free download of our programmes at our website bbcworldservice.com moreorless

[BBC Announcer]

there are dozens of different podcasts now available from the BBC, including news, documentaries, science, business, arts and sports. The details of them all, you go to bbcworldservice.com podcasts.