The following year, he traveled to the United States by himself, where he lived with a host family in Pittsburgh. It was then, in 1942, that he learned that his mother perished in Auschwitz.
Last week, Parens -- now 78 and a professor of psychiatry at Jefferson Medical College -- discussed the imprint that traumatic experiences can leave on young children.
Speaking at the Free Library of Philadelphia at Logan Square a week after Holocaust Remembrance Day, Parens addressed his audience both from a personal lens and an academic one, as a researcher who primarily studies the development of violence and rage in young children.
During the talk -- sponsored jointly by the American Jewish Committee, Operation Understanding and the Urban League of Philadelphia -- Parens said that the scars of his youth have stayed with him his entire life.
In particular, Parens, the author of a book called Renewal of Life: Healing From the Holocaust, said he continues to be haunted by a sense of survivor's guilt.
"Should I have refused to escape? Should I not have left my mother alone?" he asked aloud. "I can't help but wonder if my leaving put my mother in added danger by labeling her an undesirable" in the camp.
He also said that he's been plagued by a complicated relationship with God -- "I'm not anti-God," he emphasized, but "you have to wonder, why did God let it happen?" -- and by an inner struggle between holding on to the past, and letting go.
"I know the pain and burden this has caused my wife and three sons," he noted. While "I want to remember what happened, I also want my family to put it to rest."
But lingering wounds are only one piece of the puzzle: Many people who suffer growing up do not inflict pain on others later in life, and those who do exhibit violent behavior do not necessarily come from troubled backgrounds, noted the scholar.
Parens said that his work revolves around the idea that if the roots of childhood hostility were better understood, then they could be mended, and "we'd be more likely to rear children who don't become monsters."
The paradigm he discussed does not start with the assumption that children are born hostile. Rather, it purports that experiences of excessive pain spawn what he calls "malignant prejudice."
These experiences include individual acts of provocation, like childhood bullying, neglect or abuse, or societal traumas, such as genocide or war.
Alternatively, Parens said that hostility can calcify through the warped belief systems children absorb from their parents and from society. "Being part of a community, we differentiate ourselves from others," he said. "Groups become defined by their hatred of 'the other.' "
But not all prejudice is so malignant, he added.
Parens defined "benign prejudice" as same-group tendencies and preferences.
For example, he explained that many Jewish kids are reared to identify with other Jews, just as blacks are often most at home with other blacks. While not necessarily dangerous on its own, this in-group tendency could morph into an exclusionary policy if it became tainted with hostility, explained Parens.
Towards the close of his lecture, Parens admitted that eradicating violence is both a long-term and a multidisciplinary challenge.
Still, as he wrote in his book, "preventing tomorrow's violence" is a task that must be undertaken -- "whatever the cost."