“All the world’s a stage / And all the men and women merely players,” the Bard opens his oft-quoted play, As You Like It. “They have their exits and their entrances, / And one man in his time plays many parts.”

Comparing the world to a stage, William Shakespeare describes the seven transitional phases of man: infant, schoolboy, lover, soldier, justice, pantaloon, and elder facing death.

Today, neuroscientists say the plasticity of the human brain may allow these actors to play roles more or less interchangeably, at times kingly and others lowly. Indeed, the corrupting force of power on the human brain changes fundamentally how the mind works, according to Sukhvinder Obhi, of Wilfrid Laurier University in Ontario, Canada.

Possibly inspired by the the renowned Shakespeare Festival in nearby Stratford, Ontario, the researchers analyzed the neurobiology of people cast into varying roles, as empowered individuals or those in the role of supplicant.

Reminiscent of groundbreaking studies examining the roles of jailers and prisoner on study participants, Obhi and his colleagues analyzed the neurobiology of people cast in roles as either a powerful alpha or the supplicant. To do so, study participants in one group were asked to write autobiographically about times in life when they’d been empowered to make decisions. The other group was asked to write about times when they’d been dependent on help from others.

After this priming, Obhi and his colleagues monitored brain activity as participants watched a video of an anonymous hand repeatedly, and monotonously, squeezing a rubber ball. Looking specifically at an area of the brain known for so-called mirror neurons, the researchers sought to measure empathic feeling for other individuals. In this area, neuronal activity increases whether a person is viewing an action, such as the squeezing a ball, or performing the action.

"When I watch somebody picking up a cup of coffee, the mirror system activates the representations in my brain that would be active if I was picking up a cup of coffee," Obhi wrote in a paper published in the Journal of Experimental Psychology. "And because those representations are connected in my brain to the intentions that would normally activate them, you can get activation of the intention. So you can figure out, 'Hey, this person wants to drink coffee.'"

Interestingly, the researchers found that those cast in the role of the powerful experienced less mirroring activity in that brain area, predictive of less empathetic feeling toward others. Conversely, those in lowlier positions experienced a greater concern for their fellow man. “Perhaps the pattern of activity … we observed in the present study can begin to explain how these occurrences take place and, more generally, can shed light on the tendency for the powerful to neglect the powerless, and the tendency for the powerless to expend effort in understanding the powerful.”

In an interview with NPR on the subject, Dacher Keltner, a social psychologist at the University of California, Berkeley, said the findings match other conclusions drawn from contemporary psychological research employing brain scanning tools.

"Whether you're with a team at work [or] your family dinner, all of that hinges on how we adapt our behaviors to the behaviors of other people," he said. "And power takes a bite out of that ability, which is too bad."

However, there is some room for on-stage direction, Keltner said. Those playing powerful roles in society may be coached toward developing empathy for others, without a tragic fall from grace.