New members
Want to join us/add family?
Tel: {{healthcare_number}} Tel: 0800 414 8001

8am to 5pm, Mon - Fri

Existing members
Questions about your membership?
Tel: {{}} Tel: 0800 414 8100

8am to 8pm, Mon - Fri

Existing members
24/7 GP Advice
Tel: {{}} Tel: 0800 414 8247
24/7 Psychological Wellbeing helpline
Tel: {{}} Tel: 0800 414 8247

Open 24 hours, 7 days a week

Search site

Stress can reduce your mental ability to “that of a small child”

5th December 2014

Research released today by Benenden shows our ability to think critically, make decisions and perform reasoning tasks is significantly impaired under short-term stress.

People who believe they perform better under pressure are labouring under a false pretence, according to research which shows that acute stress negatively affects people’s ability to think critically, use reasoning and make practical day-to-day decisions.

The research, released by mutual healthcare providers Benenden and carried out by independent research company Mindlab, was carried out to discover the relationship between short-term stress and cognitive impairment.

It has been documented that long-term (chronic) stress can have a debilitating impact on a person’s wellbeing, leaving them more susceptible to psychological issues such as depression and anxiety[1]. Chronic stress is also reported to affect cognitive abilities such as learning, attention and memory[2]. However, the relationship between short-term (acute) stress and impaired reasoning and decision-making is lesser documented and understood.

In an online experiment for Benenden, Mindlab was able to put this link between short-term stress and the mind to the test.

Two groups of 100 people took part. While the control group simply took part in the tests described here, the stressed group completed a series of stress-inducing tasks before and in-between trials. The aim was to measure how short-term stress affects critical thinking and decision-making abilities. The results overwhelmingly showed that the stressed group were more likely to make the wrong decision, choose the wrong answer or react emotionally to an answer, such as make a snap judgement/decision based on a gut feeling. These traits are similar to that of small children, who tend to react to problems they don’t quite understand with an emotional (snap) response, rather than a considered logical solution.

Critical thinking

These questions included problem-solving, tested concentration and the respondents’ ability to work with a number of different facts at once. The stressed group answered just 22% of the critical questions correctly, compared to 25% of the control group. This test created problems, not unlike those that people would have to deal with in the workplace or at school or university every day, and with 88% of the participants reporting short-term stress has had a negative impact on their everyday lives and 52% saying stress affected them at least every week – it’s clear that stress, coupled with problem-solving and the need to think critically, is an unhappy and damaging partnership.

Practical decision-making

The control and the stressed group were presented with an important decision: to identify which house description out of three in the test was the best. Interestingly, 69% of the control group made the correct decision, compared to only 64% of the stressed group. A 5% difference between these small test groups shows that some of us are massively impacted by short-term stress, and are prone to make snap decisions about important life choices – such as buying a property.

Spatial abstract reasoning

The test that the stressed group found the most difficult was spatial abstract reasoning. This test looks at our ability to spot, manipulate and work with patterns and sequences. It is quite a difficult test overall, with only 44% of the control group answering all questions correctly. However, the stressed group managed just 39% - which could indicate that the more difficult the problem, the more likely stress is to affect the decision made.

Emotional Recognition

In contrast to the previous three tests, the stressed-out subjects out-performed the control group in the emotional recognition test. 77% of the stressed group were able to correctly identify the sad emotion in someone’s face, compared to 75% of the control group. This may be because stressed people are unhappy and are therefore more likely to be able to recognise and empathise with someone displaying similar traits. These results indicate that we’re affected by other people’s sadness and are tuned into unhappy, negative emotions when stressed.

Richard Carlton-Crabtree, Services Director from Benenden’s counselling service provider, Insight Healthcare, said “Many people harbour the view that a little bit of stress may be healthy as the added pressure that stress causes can positively affect their performance; but this research shows that even small amounts of stress can have negative effects. This should reassure people that they should seek help and support when the onset of stress begins because it can have a detrimental effect from day one.

“These findings also show that 79% of people tend to deal with stress on their own – which is a concerning proportion. Social support and talking through stressful situations can be the best coping mechanism. That’s why Benenden Health offers a Psychological Wellbeing 24/7 Helpline, where you can talk to someone on the phone and talk through your problems with someone equipped to help you cope and deal with them.”

Dr David Lewis, a Neuroscientist, said: "When stressed, the focus of our attention tends to narrow and, if associated with strong emotions, we tend to act less rationally on occasions. Of course, this depends both on the stressor and other factors such as personality and the coping strategies available to the individual. When stress arises unexpectedly and is especially overwhelming, rational thinking tends to be replaced by impulsive and often faulty decision making. This can be compared to a small child who responds emotionally to situations he or she finds stressful and frustrating."

Find out more about our Psychological Wellbeing 24/7 Helpline


[1] Schlotz, W., Yim, I.S., Zoccola, P.M., Jansen, L., & Schulz, P. (2011). The perceived stress reactivity scale: Measurement invariance, stability, and validity in three countries. Psychological Assessment, 23 (1), 80-94

[2] Sachinvala, N. et al., (2000). Memory, attention, function, and mood among patients with chronic posttraumatic stress disorder. Journal of Nervous Mental Disorders, 188 (12), 818-23.