Toronto resident Michael Reed said he never met Jack Layton but felt compelled to go to City Hall this week and leave one of the scores of chalk messages that have been scribbled on the wall and sidewalk in tribute of the federal NDP leader.

"Means a lot when you choke up and don’t know the person," an emotional Reed said, shortly after writing that Layton "showed us all how to always look on the bright side of life."

Reed said he believes Layton's death has had the impact it has had because Layton in part "was able to appeal to a very broad constituency."

But the outpouring of emotion when a public figure dies, seen on a much grander scale with the deaths of Princess Diana and Michael Jackson, isn't unexpected, according to some experts.

"The fact that people can identify with one another to the point of emotional contagion is part of our social being," University of Toronto psychology professor Jordan Peterson told CBC News.

"Jack Layton is a really good example of that. He's basically an abstract figure and to identify with him so tightly that his demise causes emotional stress is an amazing phenomenon."

Since Layton's death Monday, thousands of Canadians across the country have held vigils and flocked to makeshift memorials and gathering places to honour the 61-year-old politician

On Wednesday, an estimated 10,000 people had stopped to see Layton's flag-draped casket in Ottawa, with another 2,600 paying their respects the next day. Thousands more are expected to come to Toronto City Hall.

Peterson said some of it can actually be traced to before the dawn of mankind, where certain members of groups were designated "high status primates."

"The people at the top of the dominant hierarchies kind of stand for the whole hierarchy. So when the hierarchy loses its head, the entire structure is threatened," he said.

"We saw that with Kennedy's death because people just fell apart. They were acting like their whole tribe was destroyed."

Peterson added that people have the sense that they know celebrities and that they are part of our community. "More importantly they sort of stand for the community."

Peterson said he doesn’t believe greater media coverage has fuelled public reaction over the death of public figures.

"It's as old as humanity. You can see going back in history — the death of a king was always a major event."

Grief a 'well within all of us'

Diane Purvey, co-author of Private Grief, Public Mourning: The Rise of the Roadside Shrine in British Columbia, said there are some people who may get caught up in the moment, but that's not necessarily bad.

"Sometimes people call that copycat grief. But I think it can be really healthy. It’s not a bad thing," Purvey told CBC News. "It's a good thing. No doubt when people are grieving for Layton they are grieving for other loved ones who have died of cancer or their own father. Grief is sort of a well within all of us that really doesn't go away, just waiting to be triggered.

"Is there copycat grief? Are people getting on the bandwagon? Probably. Is it a bad thing? I don’t think so."

Purvey, an assistant professor in the School of Education and the Department of Philosophy, History and Politics at Thompson Rivers University, said in her research, she found people like to erect makeshift shrines and memorials because of their immediacy.

"You don’t have to go through this formal process of a funeral home. It's immediate. And it's democratic in the sense that everybody can erect a shrine. Everybody can get a piece of chalk. Everybody can write a note. It’s not expensive, whereas grieving formally has become so expensive."

"It's available to everyone and it's idiosyncratic in the sense that you can do whatever you want. You can draw a picture, you can write a note, you can put up a balloon … whatever you want to do is acceptable. There are not any formal written rules."

But Purvey said the reasons for the reaction to Layton's death are also very basic.

"No matter how you look at it, it's sad. He had this amazing victory and then to be just struck so soon. It's sad and I don't think people were prepared for it and I think that touches a chord with people."