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The Hawthorne Effect

Sunday 22 November 2015

One of the evaluation strategies used by students on the exam is the "Hawthorne Effect." This is often used as a synonym for demand characteristics. I think that this needs a bit of clarification.

Demand characteristics refer to when participants unconsciously change their behavior to meet the expectations of the research. Examples include expectancy effect and social desirability effect. Demand characteristics are different from the Hawthorne Effect. The Hawthorne effect is defined as working harding because one knows that he/she is being observed. In many studies - for example, Loftus & Palmer, it is very difficult to argue that the participants were "working harder," and thus the use of the term is not correct.

Reactivity is when individuals alter their performance or behavior due to the awareness that they are being observed. Reactivity is not limited to changes in behaviour in relation to being merely observed; it can also refer to situations where individuals alter their behavior to conform to the expectations of the observer. An experimenter effect occurs when the experimenters subtly communicate their expectations to the participants, who alter their behavior to conform to these expectations. The Pygmalion effect occurs when students alter their behavior to meet teacher expectations. Stereotype threat is one other example of reactivity.

The Hawthorne Effect is a specific example of reactivy; however, it is not a highly appropriate evaluation strategy for most psychology experiments.

Here is a typical example of the misuse of the term:

A 1978 study, to establish whether cerebellar neurostimulators could mitigate the motor dysfunction of young adults with cerebral palsy found that the Hawthorne Effect adversely affected the findings. Objective testing showed that all of patients reported that their motor functions improved and that they were happy with the treatment.

The results are more probably affected by expectancy effect, social desirability effect or conformity effects - not by the Hawthorne Effect. The Hawthorne Effect refers to the tendency of some people to work harder and perform better when they are participants in an experiment. It is difficult to see how these individuals are "working harder and performing better" in the above study.

It is important for us to recognize that the original studies that gave the “Hawthorne Effect” its name have long been discredited.

The original study and its limitations

Between 1924 and 1932 Elton Mayo carried out a series of experiments at the Hawthorne Works near Chicago. The company had commissioned studies to determine if the level of light within their building affected the productivity of the workers. Mayo found that hourly output rose when lighting was increased, but also when it was dimmed. It did not matter what was done; so long as something was changed, productivity rose.

He noticed that this effect occurred when any variable was manipulated. He concluded that it happened because the workers automatically changed their behavior. They increased output, simply because they were aware that they were being observed. He argued that the workers felt important because they were pleased to be singled out and that this factor alone accounted for any changes in behaviour.

If we only know what is outline above, we do not have a good understanding of the study. By today's standards, the study is fatally flawed. Here are some things to know about the original study.

  • Only five workers took part in the study, and two were replaced partway through for gross insubordination and low output.
  • The group’s performance didn’t always increase.
  • There were many confounding variables, such as the use of incentive pay and rest breaks. In fact, participants in the first experiment ranked “earnings” among the top three reasons why they preferred the test room over regular working conditions.
  • In some cases workers received productivity reports and often worked towards known productivity goals, which may have influenced them more than the trivial changes in working conditions.
  • Increased production was measured by the average output per day. This led to many misleading statistics. For example, lighting was always changed on a Sunday, when the plant was closed. When it reopened on Monday, output rose compared with Saturday, the last working day before the change, and continued to rise for the next couple of days. But a comparison with data for weeks when there was no experimentation showed that output always went up on Mondays. Workers tended to work harder for the first few days of the working week regardless of the lighting, before hitting a plateau and then slackening off.
  • Another of the original observations was that output fell when the trials ceased, suggesting that the act of experimentation caused increased productivity. But experimentation stopped in the summer, and it turns out from the records of production after the experiments that output tended to fall in the summer anyway. This is when most of the employees would take their holiday in order to avoid the heat of the factory.

The Hawthorne Effect today

Many modern researchers consider the Hawthorne Effect no more than a myth. What is important for us as teachers is to realize that this theory is perhaps not very helpful in understanding most research.

  • The Hawthorne effect has to do with "improvement of productivity." The fact that a person changes their behaviour simply because they are in an experiment is not the Hawthorne Effect.
  • It is not correct to say that any manipulation of an IV can cause improvement in one's behaviour. This is also not the finding of the Hawthorne experiments.
  • Changes in the dependent variables in the original study took place over many months and even years. The Hawthorne Effect is not meant to be applied to short-term exposures to changes in the IV. The actual studies looked at the manipulation of several variables over time. If the Hawthorne Effect is, in fact, valid, then it is much more complex than students realize.

Tags: Hawthorne effect, demand characteristics, reactivity, evaluation


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