'Fame' Is Good for Monkeys Too! Upward Mobility Boosts Primate Health

Fame is good. Well, at least, for monkeys. A new study suggests that the health of primates is partly determined by their "status" in their own social ladders, suggesting that upward mobility is indeed good for monkeys.

If proven, the study may help explain why people with poor backgrounds have higher rates of heart disease and diabetes. According to Noah Snyder-Mackler of Duke University, social adversity does "get under the skin."

Mackler, along with co-author Luis Barreiro of the University of Montreal and colleagues from both Duke and Emory University, led the study and observed 45 unrelated female rhesus monkeys. They slowly observed that they created a social "peking" order and found out the ones introduced earlier "ranked higher" than the last ones.

They then studied the activity of 9,000 genes in the animals' immune cells. According to New Scientist, activity in more than 1,600 genes differed between lower- and higher-ranking monkeys. This is true within "natural killer cells" or white blood cells that defend against infection. It appears these cells appear more in higher-ranking monkeys than lower-ranking ones. 

While low-rankers had stronger immune responses against bacteria, it also fueled harmful infection. Their immune cells went into "overdrive" when exposed to bacterial toxin in the lab.

Scientists explained that while a strong immune response is good, it can be damaging in unregulated numbers.

When the monkeys were re-sorted and the low-rankers became higher-rankers, startling behavior happened. The new higher-ranking monkeys enjoyed benefits such as grooming and are now less likely to trigger inflammation.

Their study suggests that stress plays an important role in the statistics other than lifestyle habits such as smoking and exercise.

According to Science Daily, people in the social ladder differ in life expectancy by more than a decade. It was previously believed that these glaring health inequalities are attributed to healthcare access and lifestyle habits, but now this new research proves otherwise. 

This means if similar molecular mechanisms underlie the link between social status and health in humans, then there can be social interventions that can be done to mitigate the physiological costs of low status.