What is the John Henry effect?

The John Henry Effect is a phenomenon where humans are more likely to persist at a task when they are in competition with a machine, even when the machine is performing the task more efficiently.

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The term is named after the African American folk hero John Henry, who is said to have competed against a steam-powered hammer in a steel-driving contest and won, only to die of exhaustion afterwards.

The John Henry Effect is often used to explain why people may be resistant to adopting new technology, even when it can improve their performance. HBR’s organizational behavior research

What is the importance of the John Henry effect?

The John Henry Effect is important because it highlights the psychological and social factors that can influence people’s perceptions and reactions to technology.

By understanding the John Henry Effect, organizations and businesses can anticipate and address resistance to new technology and develop strategies to effectively introduce and implement it.

It is also important for individuals to be aware of the John Henry Effect, so that they can recognize it in themselves and others and make more informed decisions about technology adoption. This can help to ensure that new technologies are embraced in a way that maximizes their benefits and minimizes negative impacts.

Additionally, it is important to recognize that the John Henry Effect can be a double-edged sword. It can lead to increased effort and improved performance, but it can also lead to increased stress and burnout. Therefore, it is important to find a balance between competition with machines and embracing the benefits of automation, in order to achieve optimal results.

Benefits and drawbacks of John Henry effect

Some of the potential benefits include:

Increased motivation and effort: When people are in competition with machines, they may put in more effort and work harder to try to outperform them. This can lead to improved performance and better results.
Greater acceptance of new technology: By understanding that people may be more willing to accept new technology when they feel they are in competition with it, organizations can develop strategies to introduce and implement new technology more effectively.
Higher quality work: In some cases, people may feel that machines cannot match the quality of their work and will put in extra effort to ensure a high-quality outcome.

However, there are also some potential drawbacks to the John Henry Effect, including: SHRM’s workforce research guidance

Burnout and stress: When people feel that they must constantly compete with machines, they may experience increased stress and burnout.
Resistance to automation: The competition with machines can lead to resistance to automation, even when it can improve performance and productivity.
Decreased productivity: If people are working harder to compete with machines, they may be less efficient overall, which can lead to decreased productivity.
Human error: People may make mistakes or overlook important details when they are under pressure to compete with machines, which can lead to errors and poor results.

Awareness of the John Henry effect helps HR design more rigorous program evaluations that accurately measure true workforce interventions. Using objective assessments and a structured hiring plan drives improvement, helping organizations attract and retain top talent.

Frequently asked questions

The John Henry effect is a research bias that occurs when the control group in an experiment — knowing they are being compared to an experimental group — increases their performance beyond normal levels to ‘compete.’ This inflates the apparent baseline and makes the experimental intervention appear less effective than it actually is.

The name comes from the American folk legend of John Henry, a steel driver who competed against a steam-powered drilling machine to prove human superiority. In research terms, it describes control group participants who similarly intensify their efforts when they realize they are in competition with a new intervention or method.

The Hawthorne effect occurs when experimental group subjects improve performance simply because they are being observed — regardless of the intervention. The John Henry effect occurs in the control group when they work harder due to competitive motivation. Both distort research results but through different mechanisms.

In HR, when evaluating training programs, new management practices, or engagement interventions, control groups that know they are being compared may increase their performance voluntarily. This makes the new program appear less effective than it is, potentially leading organizations to reject beneficial interventions based on flawed data.

Mitigation strategies include: using blind study designs where possible (control group does not know they are being compared), conducting pre/post measurement within single groups rather than control comparisons, using historical benchmarks instead of concurrent control groups, and acknowledging the potential bias in research design documentation.

When evaluating new HR programs, if the comparison group outperforms historical norms during the evaluation period, the John Henry effect may be a factor. HR analytics teams should monitor for unusual control group performance spikes and use multiple evaluation methods (surveys, long-term outcome data, post-program longitudinal tracking) rather than relying on single concurrent comparisons.