Mental health

Can washing your hands make you happier?

"Washing your hands makes you happier," The Mail Online reports. The idea that handwashing may help banish feelings of guilt and failure holds a powerful sway in the popular imagination – the most famous fictional example is probably Lady Macbeth's hygienic attempt to assuage her guilt for the role she played in the murder of King Duncan.

But does the act of washing your hands have any noticeable effect in real life? An unusual experiment has attempted to answer this question.

The experiment involved an "unfair" anagram test that was impossible to complete. This was then followed by an easier anagram test five minutes later.

However, in between the two tests the test subjects were put into three groups: one control group and two groups who were asked to rate how optimistic they felt about the coming test. Participants in one group were asked to wash their hands, and those in the other group were asked not to wash their hands.

The study found that the handwashing group felt more optimistic about the coming test. The researchers interpreted this effect as being caused by the physical activity of handwashing helping people to "banish" feelings of failure because they were unable to complete the unfair test.

However, the researchers found that those who felt most optimistic about their chances performed worse in the subsequent test, possibly because of complacency.

While interesting, it is hard to see what useful real life meaning or implications the study has – it is clear that washing your hands will neither make you happier nor better at tests.

Where did the story come from?

The study was carried out by a single author from the Institute of Psychology and Institute of Cognitive Science, University of Osnabrück, Germany, and was published in the peer-reviewed journal, Social Psychological and Personality Science. The author received no funding.

The Mail Online has exaggerated the implications from this small experimental study, which has rather limited real life meaning. Also, it is not until at least two-thirds into the article that the website explains that handwashing may make you more confident, but it may also make you less competent.

What kind of research was this?

Physical cleanliness is a fundamental human need that developed from our interaction with the natural environment, with the aim of avoiding physical contamination and illness.

The author discusses previous research that found that because of the inherent nature of this need, not only does physical cleansing remove dirt, it also has a psychological effect. For example, it can help ease people's guilt after any immoral behaviour, and could even make people's judgement of others' misdemeanours less severe.

The present experimental study picks up on these theories and tested whether physical cleansing after failure in a task enhances optimism about participants' future performance when faced with the same task. Perhaps more importantly, it also looked at whether washing actually affects future performance.

What did the research involve?

The study included 98 adults (71% female, average age 22 years) who were given 25 anagram word puzzles, each composed of five to seven letters. Anagrams are said to be widely used as indicators of performance in problem-solving situations. Participants were asked to solve as many anagrams as possible within five minutes.

However, only six of the 25 anagrams were actually solvable, so failure was inevitable. To add to the feeling of failure, participants were then shown a table indicating that 90% of a fictitious normal sample could achieve a high score in this test. They were then told that they would have to perform a second anagram test five minutes later.

The participants were allocated to three different groups: handwashing, non-washing and control. People in the handwashing group (32, of whom 10 were male) were asked to wash their hands before the next test for hygienic reasons, while participants in the non-washing group (33, of whom nine were male) were not asked to wash their hands.

Prior to taking the next anagram test, both the washing and non-washing groups were asked to rate on a scale of -5 to +5 how optimistic they felt about achieving a worse, the same or better score on the coming anagram test compared with the first test.

The third control group (33, of whom nine were male) only had to perform the second anagram test and were not asked about how they felt they would perform in the second test. This group was intended to give a baseline indication of performance in the second anagram test, without the "failure manipulation" – that is, they were coming to the test "fresh" without being influenced either positively or negatively.

The second anagram test consisted of 25 solvable anagrams.

What were the basic results?

Both the handwashing and non-washing groups performed to the same level in the first anagram test. But when asked to rate how they expected their performance on the second anagram test to be, those who washed their hands were significantly more optimistic (mean score 1.2 on the rating scale) than those who didn't wash their hands (mean score around 0.5).

Interestingly, both groups were optimistic – nobody gave a score below 0. However, the higher optimism in the handwashing group didn't translate into improved performance.

Performance on the second test was actually highest in the non-washing and more pessimistic group (scored just under 11), which was significantly higher than either the handwashing group or the control groups, who both scored just over 8.

How did the researchers interpret the results?

The author says that the results show that although physical cleansing enhances optimism after failure, it hampers future performance in the same task. They suggest that "the impact of physical cleansing on higher cognitive processes does not seem to be always positive, but it helps close a matter".


The study has, at first glance, rather counterintuitive results. While it seems to support previous theories that physical washing may have a beneficial effect on our feelings, in this case leading to increased optimism after previous failure, it didn't result in a subsequent beneficial outcome of improved performance.

Instead, handwashing lowered future performance on the same task so that participants performed no differently to a control group who had neither been asked to wash their hands, nor rate how optimistic they felt.

It seems that people who were asked to think about how they were going to perform in a coming task after performing badly in the first, but who were not asked to wash their hands, did the best.

In this study, handwashing seemed to increase optimism but lower performance. But, as any sports fan will tell you, being overconfident that the result is there for the taking can create complacency and lead to defeat.

While the results may be of interest in the fields of psychology and sociology, they have very limited real life meaning or implications. This small experimental study with highly artificial conditions cannot be translated to real life situations.

Even if the results do stand up in the real world, handwashing does not seem to be a particularly successful strategy. Although it may make you feel better, it seems of questionable value if it then makes you so complacent that you perform badly.

The most effective way to get better at something is, sadly, the least exciting: practice, practice and more practice.

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