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Optimism and pessimism are fundamental traits of the human brain. With optimism, there\u2019s the \u2018Just World\u2019 hypothesis, an ingrained assumption that the world is fair and that good actions will lead to good outcomes, and vice versa for bad ones.<\/p>\n
There\u2019s also the \u2018fading affect bias\u2019, where memories for negative emotional experiences fade faster than positive ones. And then there\u2019s the \u2018planning fallacy\u2019, a cognitive quirk where we constantly underestimate how long a task (such as driving to the airport) will take, regardless of how often we\u2019ve done it before.<\/p>\n
These three traits alone show that optimism infuses our perception of past, present, and future. The same goes for pessimism, however. While our memories<\/a> may skew positive, our emotion and attention systems show a negativity bias \u2013 we give more weight to and spend more time dwelling on negative experiences. And while the human brain has the impressive ability to create complex simulations of events and scenarios, much of this is used for negative or worst-case scenarios, and taboo thinking.<\/p>\n Ever stood on a cliff or high building and thought \u201cWhat if I jump?\u201d for no discernible reason? Now you know why. This is how our brain works. We need optimism to keep us motivated, to compel us to perform actions, and reassure us that we have control over our own lives. And we need pessimism to keep us grounded<\/a>, wary of risks and dangers, to make us recognise limits and restrictions.<\/p>\n A complete absence of optimism is often seen in people with severe cases of depression and anxiety, while zero pessimism can lead to unrealistic expectations, victim-blaming and harmful emotional suppression.<\/p>\n Exactly which is more important in any given situation will vary considerably, but it\u2019s impossible to deny that both optimism and pessimism are essential parts of our psyche.<\/p>\n Read more:<\/strong><\/p>\n Every week on BBC World Service,\u00a0CrowdScience<\/em>\u00a0answers listeners\u2019 questions on life, Earth and the Universe. Tune in every Friday evening on BBC World Service, or catch up online at\u00a0bbcworldservice.com\/crowdscience<\/a><\/p>\n