BBC Horizon

From Pessimist to Optimist? How Positive Actions can Change your Brain

Are you a pessimist, always preparing for failure? With so much bad news, pessimism seems reasonable and optimists can appear to be ridiculously naïve in the face of so much doom and gloom. Pessimism has its place, of course, and helps us prepare for the worst, which does sometimes happen. But, pessimism can be pervasive gradually taking over our lives with devastating consequences for our health, our wellbeing and our general peace of mind. The problem is that when you think negatively all the time, that message gets reinforced and embedded in your brain. If you start thinking, and more importantly acting more positively, however, new pathways are laid down. The more positive you are the more reinforced these new pathways will become. What I call our “rainy brain” pathways are hard to shift especially if you have been very negative for a long time. The problem is that once established these negativity pathways prepare you to respond pessimistically to most situations. The “sunny brain” pathways on the other hand underlie a more optimistic frame of mind. The more reinforced these positivity pathways become the easier it will be to respond positively in the future.

Changing Michael Mosley’s Brain

Michael MoseleyWhen Michael first came to us he said that he had always been quite pessimistic and would really like to become more optimistic. So, to try and help him overcome his pessimism and develop a more optimistic frame of mind we set him the task of undergoing mindfulness meditation as well as Cognitive Bias Modification (CBM) “positivity training” at least three times a week over a seven-week period. Unfortunately, due to time constraints Michael had to do both techniques during the same 7-week period. This means that we cannot attribute any benefits to either technique. If Michael does improve it may be all due to mindfulness, all due to CBM, or perhaps due to the combination of both techniques. The theory is that the mindfulness part should help Michael to learn to control his response to stress, improving his ability to focus and helping him to relax. The CBM part should target his unconscious tendencies to seek out the bad news. Watch the programme here…

Want to have a go yourself?

We have recreated the task we gave to Michael here so that you can try the same programme for yourself. What you will need to do is:

Take the optimism test

This will give you an indication of how you compare to other people in your general level of optimism or pessimism. Then, if you want to continue you can:

Test your cognitive bias

This task measures bias in attention and it is important to follow the instructions and keep your eyes focused on the centre of the screen as best you can. This test is much shorter than the one we gave Michael and less well controlled, but should give you a reasonable indication of whether you have a tendency to orient towards the positive or towards the negative.

Remember to take a note of your optimism and cognitive bias test results so you can compare with your scores at the end of your positivity training.

Finally, you can undergo attentional re-training or a CBM that is designed to enhance a positive bias in attention – we can call this “positivity training”. The task we used was developed by Dr Mark Baldwin at McGill University in Canada ( and Dr Stephane Dandeneau ( They kindly gave us access to their attentional training game as well as permission to give you the opportunity to try it for yourself here.

Attentional Training Game

Please note: The Attentional Training Game will not work on devices without Adobe Flash. Users with mobile devices may wish to install the MindHabits Psych Me Up! app as an alternative.

Please note:  This ‘attentional training game’ is an example of a “cognitive bias modification’ CBM technique widely used in psychological science. It is important to know that this is still an experimental technique and there is not yet enough evidence that CBM is effective as a therapy for clinical anxiety and depression. There is evidence, however, that CBM can shift negative biases in a more positive direction and the theory is that this should ultimately be helpful in overcoming negative thinking patterns. However, if you suffer from severe anxiety or depression you should seek professional help from a clinical psychologist. Your GP will be able to advise you on how to get access to clinical psychology services.

The idea is to do this task at least 3 times a week over a 6 to 8 week period. You also need to do mindfulness meditation for around 10 minutes per day, 3 days a week, over the same period.

At the end of the 7 to 8 week period, you can take the optimism test again as well as take the attention bias test to see whether there has been any change. We will also ask you some questions about whether you feel your general wellbeing has improved.

Tell us your results

Other Fun things you can do to boost your optimism and wellbeing

As I describe in Rainy Brain Sunny Brain: The New Science of Optimism and Pessimism actions are more important than thoughts when trying to change. Simple though it may seem, the simple act of smiling can improve your mood. So, make an effort to smile. (maybe we could have some pictures of nice smiley faces here?)

Having fun is also important. Psychologists have found that having at least 3 fun experiences (e.g., listening to a favourite song) for every bad experience (e.g., missing your bus) is optimal for mental health.

Breaking habits and routines is also important. So, mix things up a bit. Instead of always going the same way to work, try a new route. Do something spontaneous like going to a movie or reading a magazine you would never normally think of looking at. Here are a few more tips on how to overcome pessimism.

Want to Know More?

How do these neural pathways develop in the first place? Why do some of us have strong rainy brains, while others have robust sunny brains? Why, in a nutshell, are some of us optimists and some of us pessimists?

Psychologists have been researching this question for more than 20 years now and we are finally beginning to find an answer. The answer, I believe, has to do with the nature and strength of our cognitive biases.

Cognitive Biases are Key

At the heart of the network of pathways that underpin our pessimism or our optimism are specific cognitive biases that serve to highlight either the negative or the positive things that are going on around us. A cognitive bias is the tendency to notice, interpret, or remember the more negative aspects of life selectively. The keyword here is selectively. Life is full of uncertainties and ambiguities with lots of ups and downs, positives and negatives, going on all the time. It’s what we focus on that determines what pathways get reinforced. We can see this by thinking about the familiar “cocktail party effect”. You might be deeply engaged in conversation at a party, the music might be loud, but if someone mentions your name on the other side of the room you instantly notice. Even though you were preoccupied your brain automatically tuned in when your name was mentioned. This is a classic example of selective attention and shows that our brain is constantly monitoring our environment even when we are not aware of it.

The same happens with positive and negative information. Some peoples’ brains tune in automatically to the negative stuff, while others can filter this out and zone in on the positive. Psychologists have come up with many ingenious ways of measuring these selective biases in attention, which occur in a flash and usually happen well outside our conscious awareness. We can also measure selective biases in memory as well as biases in how we interpret ambiguous situations. For instance, people who are pessimistic remember far more negative than positive things, while optimists tend to recall relatively more positive than negative things. The key once again is selectivity. It’s not that optimists don’t remember bad things it is just that they pay relatively more attention to positive things and tend to remember the good times rather than the bad.

A very strong body of research now tells us that the pattern of cognitive biases that people show correlates with various aspects of our personality, including optimism and pessimism. Optimists, in general orient towards the positive while pessimists pay more attention to the difficulties. As Winston Churchill said “ A pessimist sees the difficulty in every opportunity, an optimist sees the opportunity in every difficulty”. We now know that these differences run deep, down in the networks and pathways that make up our rainy brain and our sunny brain. The hypothesis at the core of my research is that these biases, even when they are very minor, build up over time and have a cumulative effect. Each tiny tendency to orient towards the negative reinforces the “rainy brain” pathways embedding them even deeper and making them harder and harder to change. The good news, however, is that just as cognitive biases build neural pathways over time they can theoretically be re-trained with persistent effort. Potentially “toxic” biases that might lead to a pervasive pessimism can be reverse engineered to reveal a healthier balance between the rainy and sunny brain. That’s the theory. But, what’s the evidence?

Can a Pessimist really become an optimist?

To really change, we need to implement a deep change in our mental processes and neural pathways, and this includes changing the complex patterns of potentially toxic cognitive biases that can tip us towards extreme pessimism and even depression. Serious conditions like depression and anxiety are all characterized by strong cognitive biases to selectively notice and remember negative rather than positive information. Science now shows that these biases are not just correlated with mood disorders but can actually play a causal role in their development. In other words, persistent negative cognitive biases can result in serious mental health problems if left unchecked. Most effective treatments for anxiety and depression, including anti-depressant drug therapy as well as talking therapy, have been shown to reduce these “toxic” cognitive biases. The bigger the reduction in bias the better the recovery.

What about people who are not clinically depressed or anxious? Many people are pessimistic and would simply like to become a bit more optimistic. There is a good scientific justification for this as optimism has been shown to have lots of real benefits for our health and wellbeing.

One technique for which there is strong evidence is mindfulness meditation. This is a deceptively simple set of techniques aimed to cultivate the ability to focus awareness on the present moment. Mindfulness has been shown to have many benefits in helping both adults (see link here: and kids (see link here: learn to control destructive emotions. Before and after measures have shown that mindfulness can lead to real changes in the brain.

Another newer technique is called cognitive bias modification, or CBM (see link here: The idea of CBM is to directly tackle negative cognitive biases by means of a simple computerized programme. By presenting two images side by side very rapidly, for instance, and asking people to respond to small targets that appear in either location, we can subtly re-train the brain to shift attention away from nasty images and towards more pleasant images. A growing body of research shows that shifting negative biases is surprisingly easy and has effects on how well people cope in a stressful situation. This is still a very new technique, however, and we still need to learn a lot more about how CBM effects the pathways in the brain and whether the benefits can last for the long term.