The driver at the junction hesitates, and the once-narrow gap in traffic closes completely. This missed opportunity equals additional delay, not only for the driver in question, but also for other motorists waiting to join this busy thoroughfare. A ripple effect ensues.
One of the delayed drivers gives voice to the collective discontent with an enduring blast of his horn. Aggressively he pulls up alongside the offending vehicle - its occupants are a young woman, and her cute two-year-old daughter - but even innocence and beauty fail to mitigate his rage. Lowering the window of his truck, the envenomed driver spits vitriolic insults at a woman whose only offence was a hesitancy born of motherly love.
Anger can be an ugly emotion. Not surprisingly, Pope Gregory I included it as one of the seven cardinal sins, and the Prophet Mohammed famously counselled "la taghdab, la taghdab, la taghdab" (don't become angry).
But people still break down. According to recent research, "problem anger" is becoming increasingly common in contemporary society. A recent report by the UK's Mental Health Foundation suggests 64 per cent of the 2,000 respondents to a national anger survey either agreed, or strongly agreed, that "people in general are getting angrier". Furthermore, one third of respondents had a friend or family member who had trouble controlling their anger, and one in 10 reported themselves as experiencing similar difficulties.
I personally suspect any explanation for an increase in anger will be synonymous with explanations for the increasing prevalence of depressive illness. Psychologists have long viewed sadness and anger as two sides of the same coin. The father of psychoanalysis, Sigmund Freud, viewed anger and sadness as close cousins, if not incestuous siblings. Both emotions typically centre on themes of loss. If you lose your phone, you may oscillate between sadness at your own carelessness, and rage at the imaginary person you suspect found your phone. Freud actually conceptualised depressive illness as anger-turned-inwards.
Tellingly, both depression and problem anger are associated with similar neurochemical deficits, specifically, decreased serotonin levels. Furthermore, several studies report high levels of anger and hostility symptoms amongst depressed patients. Research at Massachusetts General Hospital in the US found that among depressed patients, 44 per cent also experienced "anger attacks", or sudden spells of anger accompanied by symptoms of autonomic activation such as rapid heartbeat, sweating, hot flashes and tightness of the chest. The World Health Organisation (WHO) projects depression will rise to become the second leading cause of disability by 2030.
These links between sadness and anger have caused a growing number of researchers and clinicians to propose that a new distinct form of depression to be added to current diagnostic systems. The proposed name for this new illness: "Irritable Hostile Depression".
The professor of psychiatry Hagop Akiskal, a leading authority on mood disorders, defines this irritability as "a persistent state of anger, a tendency to respond to events with angry outbursts or blaming others, or an exaggerated sense of frustration over minor matters".
Such irritability is presently included as a diagnostic symptom in childhood depression and bipolar disorder, but for some reason it is not included in the current diagnostic criteria for adult depressive episodes. Some suggest this omission may in part explain the sex differences in depression. Male depression, it is argued, is likely to be expressed through anger.
We can only speculate about the cost to society from undetected, untreated, irritable depression. The very reason wrath - or irrational anger - was considered a cardinal sin was that it engenders other sins. In the vernacular of the secular world, anger is often implicated in homicide, domestic violence, and yes, dangerous driving.
A better understanding of the psychological mechanisms underpinning both functional and dysfunctional emotional states is needed. Progress here can inform psycho-educational preventative interventions, enabling us to endure the slings and arrows of outrageous fortune with greater equanimity.
Justin Thomas is an assistant professor of psychology at Zayed University