The institute now plans to conduct a study of stress levels in older children too.
The study showed the stress led to errors and tumour diversity.
Creswell was also involved in a 2009 study that showed just two 10-minute affirmation writing activities in the weeks leading up to a test were sufficient to relieve the study subjects' stress-related reaction to the examination.
Those with college education who were also employed had significantly less stress, which the study authors suggested could be a result of having access to additional support networks, adult interactions and income to relieve stress.
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Rebecca Wood, chief executive of the Alzheimer's Research Trust, said it was important to stress that the study only focussed on people with pre-existing memory conditions.
In other words, the diminution of memory in the poorer members of their study was entirely explained by stress, rather than by any more general aspect of poverty.
In what the researchers said is the largest project to examine leadership and stress, the study recruited 148 leaders and 65 non-leaders from the Boston metro area and from a Harvard executive education program designed for senior-level officials in the public sector, which included members of the military.
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Our study suggests strong heritabilities to work stress and the outcomes of stress.
However, he was quick to stress that while a study of evolution may tell us how we came to be, it says nothing about what we should strive to become.
Glynn said the study also showed that emotional responses to stress are greater earlier in pregnancy.
To determine stress levels, the researchers measured the levels of salivary cortisol, a stress hormone, in the study subjects.
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Over the past two years, the economy has nose-dived into recession and joblessness has climbed -- and, as the study notes, unemployment is associated with stress and alcohol use.
Compared to controls, the rats also showed increased sensitivity to stress and produced more of a stress hormone, in a study published in May in a Public Library of Science journal, PLoS One.
The study did not clarify whether the babies' stress levels lowered as their sleep patterns settle over time.
The study found a correlation between the increase in stress and the number of days holiday taken by executives in the countries concerned.
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More study is needed to see how the mental stress test relates to traditional exercise testing, said Dr. Eric Rashba, professor of medicine at Stony Brook University Medical Center in Stony Brook, New York.
And earlier this year, a study found that when mice are subjected to stress over a period of time, they have more phosphorylated tau protein deposits in their brains (see this Scientific American blog for a nice synopsis).
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Dr Evans's and Dr Schamberg's study does not examine the nature of the stress that the children of the poor are exposed to, but it is now well established that poor adults live stressful lives, and not just for the obvious reason that poverty brings uncertainty about the future.
The authors of the study point out that the link between holidays and stress could go either way.
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According to a study reported in the ABA Journal, lawyers under stress are tense, overly critical, cautious and emotionally distant.
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Monkey behaviour may help to explain why middle managers suffer the most stress at work, according to a study at two leading universities.
Still, caffeine can cause some "cellular stress" to organisms, and another study this month will expose mussels to similar doses of caffeine to see its effects on their reproductive activity.
As the Nature piece notes, a 2010 study found that reports of drought-related forest stress and destruction had risen steadily since 1985 in varied ecosystems around the world, and suggested the pattern was tied to climate change.
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In their study, Creswell and his colleagues asked participants about their stress levels over the previous month.
The Swedish study builds off the established idea in the field that stress actually harms the brain.
They wanted to study how much willpower someone had in a time of stress - in this case, during exams.
According to the 2011 study, they have a more muted or "buffered" stress response.
Another study found that canines, as in dogs, reduce workplace stress, too.
The authors of this study say as children mature, they require less care and stress for parents -- and can become a source of support for moms and dads.
She has chosen 51 genes to study, including those involved in the body's responses to stress and infection, in hormonal changes related to pregnancy, and in ways in which the body handles a wide variety of environmental toxins.
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