May 15

The Birth of Tragedy: Pessimism and the Brain (Part 2)

Is the resolve to be so scientific about everything perhaps a kind of fear of, an escape from, pessimism? – Friedrich Nietzsche

In the first part of this article we examined contrasts in attitude and outlook between optimistic and pessimistic people and possible differences in the brain leading to these contrasts. The next question is, since most people (at least in the cultural ‘West’) seem to be unrealistically optimistic, how can we account for the development of the pessimistic brain? And is there a way to reverse the process, to clinically turn that frown upside down?

‘Wait,’ I hear from my diligent readers who of course have read part 1 thoroughly, ‘I thought one of the takeaways was that pessimistic people have a more realistic view of life? Shouldn’t we want more pessimistic people, not less?’ While there is evidence that indeed, lightly-to-moderately pessimistic people do have a view of life closer to their reality than some of their more optimistic and more intensely-pessimistic peers, there are a number of drawbacks to being a pessimist, related to findings that those with a pessimistic outlook have worse health outcomes (1,2) and worse mental health (3,4). These differences manifest from both physiological and behavioral differences between the two groups. For a physiological example, one study found that optimists blood pressure was lower compared to pessimists when performing the same stressful task (5).  Behaviorally, optimists are more likely to likely to set positive health goals and initiate action to achieve these positive changes in their life (6).

What creates pessimism as opposed to optimism?

A deceptively simple task used with humans and animals illustrates how pessimists/optimists can take the same information and draw very different conclusions. In this task, when animals are shown a first color, they must press the first lever to get a reward. When they are shown a second color, they must press the second lever to avoid a punishment. After training, the animal is shown ambiguous colors which are each a combination of different percentages of the reward color and the punishment color (Figure 1). For example, if the color is closer to the reward (70% reward/30% punishment) the animal should press the reward lever. A pessimistic animal will push the punishment bar in response to colors which are a greater percentage reward than punishment, presumably displaying a greater fear of their actions having negative consequences rather than a belief that their actions will be rewarded.


Figure 1. This is an illustration of the ‘ambiguous cue’ task. A) Animals are trained to press one lever in response to a dark grey square to receive a reward. They are trained to press a second lever in response to the light grey square to avoid a punishment. B) Then the animal is shown cues that are ambiguous in that they are a mix of both the positive and negative stimuli. Both an optimistic and pessimistic animal will respond correctly to ambiguous cues that are close to either the reward or punishment color. But optimists will assume that squares that are equal parts reward and punishment are reward stimuli while pessimistic animals will assume that the same squares are punishment stimuli. This is the essence of the divide between optimists and pessimists: when presented with the exact same information, they will respond differently based on their biases.

This test has identified pessimistic tendencies in species as diverse as rats (7), cows (8), and bees (9) and similar tests have found the same divides in humans (10,11). In animals, these tests are often done after an animal has had something negative happen to it to determine if these animals have become more pessimistic. For example, rats (7) that consistently lost fights to other rats became more pessimistic than they were before they began to get into fights. Similarly, bees (9) that were shaken to simulate a predator attack showed more pessimistic decision making after the simulated attack than before. These tests suggest that pessimism may come about as the result of experiencing negative events.

Studies in humans have found indirectly supporting evidence to the animal studies. The socioeconomic status (SES) of a child is an important predictor of whether a child will develop into a pessimist. Knowing the SES of a child between ages 3-6 helped to predict increased pessimism later in life, regardless of if the child grew up and improved their SES (12). Another study found that as childhood adversity increased, optimism decreased (13). Taken together with the animal evidence that negative events increase pessimism, and assuming low SES leads to an increase in negative events experienced, this suggests that pessimism is tied to the amount of negative events you have experienced.

When examining the interplay of genetics and environment, further evidence was found supporting the idea that life experiences play a large role in the development of pessimism. Three studies of fraternal and identical twins, either raised separately (meaning their similarity would likely be due to shared genetics) or raised together (meaning their similarity would be due to both shared genetics and shared environment) found that optimism and pessimism were definitely related in some aspects to genetics but that environment played a large role (14,15,16). Studies focusing exclusively on environmental factors have found that factors such as parents and teachers affect the development of the child’s optimism or pessimism (17).

As in most questions of complex cognitive constructs, the answer appears to be partially genetic and partially environmental. In this case it is not yet known to what degree each part plays a role, but the environmental experiences of an individual appear to play a larger part. Combining the environmental genetic evidence with the neuroscientific evidence (from the first part), it would appear that some individuals are predisposed to cognitive biases that increase the likelihood of developing a pessimistic outlook. These include being more likely to notice a negative event or being more likely to update expectations in response to experiencing a negative event. Some of these individuals may maintain an optimistic outlook if they do not experience many negative events, but on the whole these individuals would be expected to be more pessimistic than someone who had experienced a similar number of negative events but who did not share their vulnerabilities.

Pessimism & Outcomes

So what hope is there for those who would like to avoid the health & mental drawbacks of being a pessimist? First the bad news: optimism and pessimism are thought to be a stable part of your personality (18). However, there is some evidence that therapy can successfully alter one’s outlook. Working with adolescents the Penn Resiliency Program has shown evidence that creating an awareness of negative thinking and facilitating the adoption of a more constructive outlook can improve pessimistic tendencies (19). Other interventions focus indirectly on pessimism by attempting to improve some of its symptoms such as anxiety and depression. Mindfulness-based interventions have a strong track record for improving both anxiety and depression over multiple studies (20). These practices involve focusing on present moment feelings and a non-judgmental acceptance of how one feels. This is hypothesized to counter automatic orientation toward thinking about the future (which for pessimists is very stressful) and a more reflective imagining of how future occurrences will turn out. A last approach is Cognitive Bias Modification which has been found to improve anxiety but not depression (21). This practice focuses on changing our automatic responses to stimuli. For example, a stressed person may notice threatening stimuli more than pleasant stimuli; this automatic response can be slowly changed through training.

Overall, it appears there is some evidence for slightly depressed individuals having a more realistic outlook on life, but at the cost of possible consequences for their health. The differences in outlook have roots deep in the brain, to the point that optimists and pessimists may not even notice the same evidence and even if they do they have wildly different explanations for what they see. If someone wanted to change, it would require some hard work to fight against ingrained information processing systems in the brain.

If you are optimistic, congratulations! But perhaps try to tone down that good feeling a little bit; noticing the negative can improve your planning and ability to foresee obstacles. If you are intensely pessimistic, try to cheer up! It will be difficult overcome your tendencies and to see the bright side of life, but the reality you’re perceiving is no less wrong than the optimists (you’re just miserable because of it). If you are mildly pessimistic, you have a choice to make! Continue with your realistic interpretations of the world in front of you, or try to skew just a bit happier in an attempt to improve your health and mental well-being.


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