Researchers from Manchester University and Liverpool University observing monkeys found that those in the middle hierarchy suffer the most stress due to social conflict.
Katie Edwards from Liverpool's Institute of Integrative Biology spent nearly 600 hours watching female Barbary macaques at Trentham Monkey Forest in Staffordshire.
Her research involved monitoring a single female over one day, recording all incidents of social behaviour. These included agonistic behaviour like threats, chases and slaps, submissive behaviour like displacing, screaming, grimacing and hind-quarter presentation and affiliative behaviour such as teeth chatter, embracing and grooming.
"Not unsurprisingly we recorded the highest level of stress hormones on the days following agonistic behaviour. However, we didn't find a link between lower stress hormone levels and affiliative behaviour such as grooming," Edwards explained.
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Another key aspect of the research was noting where the observed monkey ranked in the social hierarchy of the group. The researchers found that monkeys from the middle order had the highest recorded levels of stress hormones.
"What we found was that monkeys in the middle of the hierarchy are involved with conflict from those below them as well as from above, whereas those in the bottom of the hierarchy distance themselves from conflict," said Dr Susanne Shultz, a Royal Society University Research Fellow in the Faculty of Life Sciences at The University of Manchester oversaw the study.
Edwards said the results could also be applied to human behaviour.
"It's possible to apply these findings to other social species too, including human hierarchies. People working in middle management might have higher levels of stress hormones compared to their boss at the top or the workers they manage," she said.
"These ambitious mid-ranking people may want to access the higher-ranking lifestyle which could mean facing more challenges, whilst also having to maintain their authority over lower-ranking workers," she added.