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One in four of us will experience debilitating anxiety in our lifetime. But let’s be clear, emotions are not part of us simply to be ‘felt’ or ‘experienced’; emotions have evolved as a central feature of human nature because they serve a function – an evolutionary function. Individual emotions will facilitate reproductive success or help us to identify and deal with specific challenges to reproductive fitness – that is why, after thousands of years of human evolution, we still experience emotions. And anxiety is no exception to this.
Anxiety is often a distressing emotion, and one that often feels debilitating rather than enabling. So what advantages does anxiety bring, if any? First, anxiety is associated with some important shifts in attention to events and in the way you process information. When you feel anxious, you will automatically preferentially allocate attention to things you find potentially threatening (such as someone frowning who is crossing the road and walking towards you), or information that is threatening (for example, details on a TV programme describing increases in crime in your area). This shift in attention to things that may be threatening occurs automatically and pre-consciously – that is, your attention will have shifted to focus on the threat before you realize it’s happened![1] This is one of anxiety’s many double-edged swords. This attention shift has the advantage of keeping you alert and focused on potential threats, and this increases the opportunity for you to nullify or avoid the threat. But it can also get you into a vicious cycle because attending automatically to things that might be threats will also increase your anxiety! For many people, the effect of this vicious cycle can be difficult to manage and is one source of chronic anxiety in some people.
Another consequence of this attentional bias to threat is that it also affects how you interpret events around you. Much of what we encounter in our everyday lives is ambiguous. By that, I mean they’re not obviously positive or negative, benign or threatening — we have to make some additional judgments to decide whether something is good or bad for us. Let’s imagine you overhear a friend saying that your speech at a recent wedding reception had made her giggle. Good thing or bad thing? Well, it’s ambiguous, isn’t it? She may have loved your speech because it made her laugh, or she may have giggled out of embarrassment because it was so bad! However, if you hear this remark while feeling anxious, you’ll have a strong tendency to automatically accept the negative interpretation[2]. In an evolutionary or adaptive sense, anxiety is doing you a favour here. It’s making you alert to potential threats that will enable you to focus on dealing with them. But psychologically it can be pretty emotionally demanding, because this process will also make you interpret many things as threats that turn out not to be threats (i.e. you’ve interpreted them negatively when they are in fact benign).
So, does anxiety actually work in practice? Does feeling anxious really bestow practical, adaptive advantages? Well, yes, it seems it does. William Lee, a psychiatrist at the Institute of Psychiatry looked at the lives of 5,362 people born in 1946. He discovered that those who exhibited high levels of anxiety (based on ratings by their teachers when they were 13 years old) were significantly less likely to die an accidental death than those with low anxiety[3]. Only 0.1 percent of the anxious individuals died accidentally compared with 0.72 per cent of the nonanxious individuals. There was no difference between the two groups on the number of non-accidental deaths. But here swings anxiety’s double-edged sword again. After 25-years of age, the anxious individuals started to exhibit higher mortality rates due to illness-related deaths than their nonanxious counterparts. Lee and his colleagues concluded that their results “suggest there are survival benefits of increased trait anxiety in early adult life, but these may be balanced by corresponding survival deficits in later life associated with medical problems." What anxiety gives with one hand, it takes away with another. But there is a clear evolutionary benefit here. Anxiety helps people survive potential accidental deaths until they’re well into early adulthood — a time when they are likely to be at their reproductive peak. This means they are more likely to survive to early adulthood to reproduce successfully than nonanxious individuals, and so their genes are more likely to survive into future generations. But once you’ve propagated your genes into future generations, anxiety then cares little for you and you are more likely to die of other medical ailments than the nonanxious individual!
In a different series of studies, psychologists Tsachi Ein-Dor and Orgad Tal from the Interdisciplinary Centre Herzliya in Israel conducted a number of imaginative experiments on worriers and high anxious individuals. First, they found that worriers sense threats – such as detecting the smell of smoke - much faster than their nonanxious counterparts[4]. In a second experiment, they found that high anxious individuals are also much less likely to get distracted when attempting to deal with a potential threat or problem[5]. In this latter experiment, participants were asked to complete a computer assignment but the programme developed a virus, which the participant was told they had activated (but they actually hadn’t, it was automatically activated as part of the experiment!), they were then told they should seek technical support urgently. As they tried to do this they were presented with a number of additional ‘obstacles’ such as a student dropping a stack of papers at their feet, and another asking them to complete a survey. Anxious participants were the least likely to be distracted by these challenges, and were more likely to get the required technical support quickest!
But just as we found with anxiety, worry too has two quite different sides to its character. While worry maintains your awareness of forthcoming dangers and helps you to think through possible solutions to deal with the danger, it too is associated with negative longer-term effects. In a study entitled "Is Worrying Bad for Your Heart?" Laura Kubzansky and colleagues asked 1,759 men free of chronic heart disease in 1975 to complete a questionnaire asking the extent to which they worried about each of five worry domains — social conditions, health, financial, self-definition, and ageing[6]. Over the following 20 years they recorded the incidence of heart disease. They found a significant relationship between worry severity and the subsequent risk of chronic heart disease, and in elderly men worrying predicted the risk of a second heart attack after having already experienced a first attack. A further study investigating the psychological effects of the 9/11 attacks in New York found that in those US citizens exhibiting extreme stress after the attacks, ongoing worries about terrorism predicted cardiovascular health problems up to 2 and 3 years after the attack[7].
And it’s not just a heightened risk of cardiovascular problems that’s associated with anxiety. A study that recently tracked 15,938 Britons over 40 years of age found that men who had a lifelong diagnosis of generalized anxiety disorder were 2.15 times more likely to die of cancer than those without the anxiety diagnosis – even when factors that are likely to cause cancer, such as age, alcohol consumption, smoking, and chronic disease were accounted for[8]. It’s not clear from the study what the exact link is between anxiety and cancer, but it’s clear that we need to consider anxiety as a warning signal for poor health in later life.
The story seems to be a consistent one. Yes, anxiety and its associated features such as worry do appear to have real adaptive benefits. They help you keep future dangers in mind, they give you the ability to process information automatically in a way that will maintain your focus on these dangers – often in a single-minded way - and productive worry may even help you find solutions to deal with the dangers and threats. To bolster these positive aspects of anxiety, there is evidence of real, practical benefits to these processes in the form of fewer accidental deaths among anxious individuals in young adulthood. But anxiety cares little about you as you get older. There is an increased health-related mortality in older anxious individuals as well as a higher risk of specific illnesses such as cardiovascular disease. My suspicion is that, once you are older, anxiety will have assumed it has already done its job, so cares rather less about you than when you were a young adult. In evolutionary terms, the selective impact of anxiety is likely to be highest when it comes to ensuring that each individual can propagate his or her genes successfully. So anxiety will keep you alive until an age where you are most likely to have produced offspring[9]. Then its job is done! It’s as if a lifetime of high anxiety shifts most of the positive effects of your life energy into the early half of your life, only to leave you to burn out prematurely in the latter half. So, if you’re an anxious person it may be cold comfort to you that anxiety has seen you through to being a parent, but may then be trying to kill you off relatively quickly in later life!
[1] Mogg K & Bradley BP (1998) A cognitive-motivational analysis of anxiety. Behaviour Research & Therapy, 36, 809-848.
[2] Eysenck, M. W., Mogg, K., May, J., Richards, A., & Mathews, A. (1991). Bias in interpretation of ambiguous sentences related to threat in anxiety. Journal of Abnormal Psychology, 100, 144–150
[3] Lee W E, Wadsworth M E J & Hotopf M (2006) The protective role of trait anxiety: A longitudinal cohort study. Psychological Medicine, 36, 345-351.
[4] Ein-Dor T, Mikulincer M & Shaver P R (2011) Effective reaction to danger: Attachment insecurities predict behavioural reactions to an experimentally induced threat above and beyond general personality traits. Social Psychology & Personality Science, 2, 467-473.
[5] Ein-Dor T & Tal O (2012) Scared saviors: Evidence that people high in attachment anxiety are more effective in alerting others to threat. European Journal of Social psychology, 42, 667-671.
[6] Kubzansky L D, Kawachi I, Spiro A, Weiss S T, Vokonas P S & Sparrow D (1997) Is worrying bad for your heart? Circulation, 95, doi.org/10.1161/01.CIR.95.4.818.
[7] Holman, E. A., Silver, R. C., Poulin, M., Andersen, J., Gil-Rivas, V., & McIntosh, D. N. (2008). Terrorism, acute stress, and cardiovascular health: a 3-year national study following the September 11th attacks. Archives of General Psychiatry, 65, 73-80
[8] http://medicalxpress.com/news/2016-09-men-anxiety-die-cancer.html
[9] The age of first-time parents has risen significantly in the past few decades. In the UK in 2014 the average age of a first-time mother was 28-years of age, and a first time father was 32-years of age. But these are still ages where the heightened risk of anxiety-related mortality is likely to be very low.
