With the winter here, 'tis the season to be sick.
We warily aim the antibacterial spray at those coughing and spluttering around us. But, the lurgy isn't the only thing we can catch from our co-workers.
Stress can be as as contagious as a cold, new research has found.
With about three-quarters of us feeling stressed, it is endemic.
A team of psychologists from Saint Louis University wanted to know how susceptible strangers were to 'secondhand stress'.
To test the theory, they took a group of participants and asked some to perform a public speaking or mental arithmetic challenge while the others observed.
The researchers measured the levels of cortisol and a stress-related salivary enzyme in the stressed speakers and the observers.
They found that the stress response in the witnesses was "proportional to that of their paired speakers and not influenced by gender".
Stress can be passed on through things like tone of voice, facial expressions, posture and even odour.
“To find that in some people, some of the time, you can elicit these responses just by sitting and watching someone else under stress was somewhat surprising to us,” Tony Buchanan, associate professor in the Department of Psychology at Saint Louis University, told ABC.
A separate, small-scale study by the University of California, in collaboration with New York University, found that stress can resonate even in the aftermath of a tense experience.
The researchers separated a group of mothers from their babies for a short period. The mothers were then divided into groups and asked to give an impromptu speech to a panel, who watched passively, with positive facial expressions or whilst scowling.
The babies were then reunited with their mothers and both their heart rates were measured. It was found that the baby's heart rates mirrored that of their mother.
"The greater the mother’s stress response, the greater the infant’s stress response – an association that actually became stronger over time," the authors said.
By studying the effect, the researchers hope to create more awareness about how we impact on those around us and how we are impacted on by them.
"Emotions are not simply concepts that live privately in the mind, but rather affective states that emanate from the individual and may influence others," they wrote.
The researchers from the Saint Louis study also hope to develop their understanding of what causes variability in our stress response.
The more empathy you have, the stronger the resonance is likely to be.
And the deeper the desire will be to help the person in distress, for instance.
"Just as contagious stress is thought to promote rescue behaviours in ants," the study's authors said.
But, it can also evoke antisocial or ambivalent tendencies.
"Individuals will actually respond pro-socially during stress when the target is vulnerable, distressed, socially bonded or interdependent and when the observer does not fear for their own safety or security, does not have conflicting personal goals, and knows what needs to be done," they said.
"With additional research, across species and domains, we can provide a more complete picture of how stress guides our decisions for good and for ill."
Stress is not necessarily negative – it can help us.
"The physiological stress response evolved as an adaptive way to motivate behaviour and release metabolic energy in situations of acute need," say the Saint Louis study authors.
It can make us act quickly to get out of harm's way. The ability to meerkat-like pick up on stress signals in others leads to heroism and acts of altruism.
The thing with stress is that it puts off longer-term processes, like wound healing and digestion, growth and immune function.
So, here and there it is helpful. Chronically, it can be incredibly damaging and increases our risk of heart attack, stroke and depression.
A new study has also found that chronic stress may alter the parts of the brain responsible for learning, memory, and the processing of stress and emotion.
To manage stress the Australian Psychological Association recommends seven steps.
1. Identify warning signs like teeth-grinding or irritability.
2. Identify triggers: for example, late-nights, deadlines, seeing certain people or hunger.
3. Establish routines: rhythms and managing time can be soothing.
4. Look after your health: eat well and exercise regularly. Also, "Take time to do activities you find calming or uplifting, such as listening to music, walking or dancing. Avoid using alcohol, tobacco or other drugs to cope."
5. Notice your "self-talk": swap "I can't cope", or "I'm too busy", or "I'm so tired", or "It's not fair" with "I'm coping well given what's on my plate" or "calm down" or "breathe easy".
6. Spend time with people who care and don't bottle up your feelings.
7. Practise relaxation: yoga, meditation or breathing exercises. If all else fails, seek help.