New Research Reveals How Changes in Social Status Impact the Brain
The study conducted in male mice found that bigger social tumbles are more stressful.
Imaging of the mouse brain with key gene highlighted by blue stain. The University of Texas at Austin.
Social hierarchies are everywhere, from the workplace to the wilderness, subtly shaping behaviors and relationships. But what happens in the brain when someone’s social rank changes? A new study from researchers at The University of Texas at Austin found that those at the top of the social hierarchy experienced more stress when they dropped in social rank; they also experienced more changes within the brain than those that climbed the social ladder.
The bottom line? It’s not easy at the top.
“We found that social reorganization is most stressful for the dominant individuals compared to the subordinates,” said Hans Hofmann, professor of integrative biology, who led a study that repeatedly shuffled hierarchies in mice. “Even those that remained at the top experienced considerable stress levels. The ones who started at the top and fell in rank, experienced the most stress and changes. The farther you fall, the more stressful it is.”
The study, out last week in the journal PLOS Genetics, explores the behavioral, physiological and molecular consequences of social transitions in male mice. The findings reveal an interplay between social rank, stress and gene expression, offering new insights into the biological basis of social plasticity.
Researchers placed the mice in enclosed groups of four and observed them for 10 days, noting that social hierarchies formed within about 10 minutes and mice established clear ranks with the alpha male at the top and the omega male at the bottom. After 10 days, researchers then mixed the groups. Hierarchies were again established within the first few minutes. The team members observed the changes in the levels of stress hormones in the blood of all the mice, as well as monitored brain activity, particularly changes in how the genes in the brain were expressed. In particular, they examined gene expression in the medial amygdala, a region of the brain central to regulating social behavior.
“We found a set of genes that appear to regulate social transitions, regardless of the direction of the social change, in the medial amygdala,” said James Curley, professor of psychology at UT Austin and corresponding author on the paper. “These genes could be critical to understanding how animals adapt to dynamic social situations more generally.”
Previous research has established that in humans this part of the brain is involved in processing social rank and hierarchies, while other observational studies have found that people reported increased stress when they experienced social status changes, such as the loss of a job or financial hardship. While the authors of the new study pointed out important differences in social systems between humans and mice suggest applying caution in drawing comparisons between the two, they also note that the study could provide pathways for future research into human mental health and well-being in the wake of major life events.
“This study opens a lot of doors because no one has really looked at the effects of social ascent and descent in this way,” Hofmann said, referring to identifying genes and molecular pathways within the brain linked to changes in social rank.
Tyler Milewski, Won Lee and Becca Young of UT Austin were also authors on the paper.
