We're accustomed to stories about childhood bullies, but similar behaviours are occurring among seniors in independent retirement communities, assisted-living facilities, nursing homes and community centres.
"People in these places bully each other, although we don't always perceive it as such,'' said Dr Matthew Coppola, a primary-care physician at Allegheny General Hospital in Pittsburgh who treats a number of geriatric patients.
In response to reports from staff, he has begun speaking at senior facilities on the topic of "bullying in your golden years.''
The goal is help residents identify bullying, protect themselves by speaking up or telling staff and decide what do to when they witness bullying of others. He also works with staff to draft bullying policies and enforcement procedures.
This is not about older people whomping each other with their walkers, but tends to involve social pressure from nasty comments, gossip, cliques and shunning.
Seniors can be the victims, the perpetrators or both.
"One of my patients described it as junior high all over again,'' said Dr Andrea Fox, a gerontologist and medical director of the Squirrel Hill Health Center in Pittsburgh.
Coppola said that based on his experience with geriatric patients, "bullying occurs everywhere.''
And he should recognise it: As one of six children, he's been on the giving and receiving end many times, and with six children of his own, he's done plenty of refereeing.
"I believe everyone is bullied at some point,'' he said, but that doesn't mean it should be ignored, especially among vulnerable populations where depression, loneliness and isolation can result.
"I've watched my senior patients going through different phases of their lives, and their golden years aren't always so golden,'' Coppola said.
"They need assistance where they didn't before, and they have to adjust to a new environment. Sometimes they resort to bullying to get the task accomplished.''
A small pilot study by Robin Bonifas at Arizona State University in Phoenix found that 10 per cent to 20 per cent of seniors in care homes are mistreated by peers.
"People don't see it as a problem because it's just the way people are, but it can lead to residents not wanting to leave their rooms,'' said Bonifas, an assistant professor at the School of Social Work. She just completed the second phase of her 19-month study.
Bonifas, who holds a PhD in social welfare, interviewed seniors at two assisted-living places where 24 of 130 residents came forward to say said they'd felt threatened by peers.
A third of the complaints wouldn't meet the definition of bullying, she said - for example, an impaired person yelling at a wall - but the residents felt threatened anyway.
"I don't know that there's hitting or kicking, although there could be, but most complaints were about emotional or psychological things such as excluding people from groups, making fun of them and gossiping.''
Bullying may be a function of cognitive problems, said Dr Fox, who is also an associate professor of family medicine at the University of Pittsburgh School of Medicine.
"People tend to develop cognitive impairment as they age and also become more disinhibited,'' she said.
"My grandmother was living in a senior high-rise in Los Angeles, and she started to get demented. She kept losing things and yelling at people for stealing from her.''
But cognitive problems are hardly a prerequisite, she said.
Bonifas said her study looked at social history, self-esteem, history of trauma, mood and cognitive status. The last was not a predictor, she said, but that could be due to the small size of the sample.
She is looking to do a larger national study soon.
"In nursing homes, cognitive status does play a role, but we don't see bullying there as much as outright behavioural problems and impulse-control issues, not being able to judge what's appropriate.''
More often, she said, bullying is related to loss and an extreme need to maintain control.