Some interesting research on child development and violence…

Could educated, deliberate parenting skills reduce suicidal, depressive, or violent behavior? Maybe. You decide.

“Skills in parenting are key to facilitating healthy development in children. Qualities of parenting that have been found to be related to healthy development vary by age of the child. They range from the sensitive, responsive caregiving especially needed by infants to the monitoring that is particularly needed by adolescents. Important aspects of effective parenting across development include providing age-appropriate levels of warmth and structure to help children feel safe and to help regulate their emotions (e.g., Cole, Martin, and Dennis, 2004).

Excerpt from

Comparing development from nature and nurture… An excerpt from the transcript of “Mind off a Rampage Killer”

“JOSH BUCKHOLTZ: When we compare people who commit violent acts against people who don’t commit violent acts, some brain differences begin to emerge: differences in brain circuitry that’s involved in emotional arousal and emotion regulation.

MILES O’BRIEN: One of these circuits connects the prefrontal cortex, responsible for higher level thinking, to the amygdala, an emotion center, which goes into overdrive whenever a threat is perceived. If the threat is not real, the prefrontal cortex will send a message to the amygdala to calm down, but if the wiring is faulty, that calming message may not get through.

JOSH BUCKHOLTZ: And in those folks, it seems like this circuit is broken in such a way that they’re more likely to respond with greater amygdala activity and greater emotional arousal, when they think that they’re being faced with some kind of threat.

MILES O’BRIEN: So what can break or damage this crucial circuit? At least part of the answer lies in the genes we inherit from our parents. Buckholtz and others have found that certain genes can compromise this wiring. But here’s the tricky part: even if people have those genes and their wiring appears weak, there’s no guarantee they will end up violent.

JOSH BUCKHOLTZ: There’s no one single gene, there’s not even 10 single genes that, on their own, predispose people to become violent. What we know about complex behaviors generally and violence specifically is that the genetic architecture is very complicated.

MILES O’BRIEN: When it comes to the brain and people’s behavior, evidence points to a complex dance between genes and the environment: nature and nurture.

PAUL FRICK: Everything we talk about in psychology is both nature and nurture. So the trick is to find out, how do they both operate? It’s never one or the other, never.

MILES O’BRIEN: Key clues to how nature and nurture might operate to shape the brain are emerging from studying families.

And some of the best evidence is coming from these families: rats. Remarkably, researchers discovered that baby rats who were licked frequently by their mothers grew up to be calmer and gentler adults. But if the mother was standoffish, when the babies grew up, their biology and behavior was different.

MICHAEL MEANEY (McGill University): What we were particularly interested in is the way in which these animals might respond to stressful events. And we found the offspring of low-licking mothers, during periods of stress, show greater increases in blood pressure and greater increases in stress hormone production.

MOSHE SZYF (McGill University): They will scream. They will try to bite you. Just walking into their cage, those rats will respond differently.

MILES O’BRIEN: Moshe Szyf and Michael Meaney, of McGill University, knew this violent behavior was not strictly inherited, because it happened even when the caretaker was unrelated and long after the rats were grown. Could it be that nurture was trumping nature, somehow changing the way the genes worked?

MOSHE SZYF: The behavior of the mother has an impact on the offspring, years after the mother is already gone. And we reasoned that there must be some mark in genes that marks that memory.

MILES O’BRIEN: Studying the brain cells of the calm and stressed out rats, they found that different genes were getting turned on or off in the babies, depending on how they were treated.

When a baby was licked and cuddled, cells in the rat’s hippocampus, a part of the brain that helps regulate emotion, turned on a gene that reduces stress hormones. But if the baby was neglected, a chemical chain reaction began that effectively shut down the gene, causing stress hormones to soar. And, amazingly, these changes would stick, long after the baby grew up.

KARLEN LYONS-RUTH: What we’ve learned from animal models, which was pretty astounding, is that the quality of maternal care in the first week of the rat baby’s life, sets up the stress response system in the baby.

MILES O’BRIEN: Harvard researcher Karlen Lyons-Ruth doesn’t study rats. She studies people.

Of course, there are differences between rats and humans, but she’s finding we might have a lot in common, particularly when it comes to the relationship between parent and child and how it can impact the way the child will respond to stress throughout his or her life.

It started with a simple, yet revealing experiment called “the strange situation.”

Here’s how it works: the baby is placed in a room with some toys; the parent leaves; the baby, predictably, gets upset. Next, a stranger comes in and tries to provide some comfort. No luck. The baby just wants his mom. So in comes the parent. What happens next is what Lyons-Ruth finds fascinating.

KARLEN LYONS-RUTH: We’re interested in how the baby responds to stress and then how the parent is able to help the baby regulate that stress.

MILES O’BRIEN: Most of the time, it is a happy ending, like this one, but things don’t always go so well.

The Lyons-Ruth research videos, now 30 years old, have never been shown outside a narrow circle of scientists. To protect the identities of the participants, we obscured them digitally.

KARLEN LYONS-RUTH: You see the mother come in, so, you hear the mom enter silently. It’s a threatening approach. We usually signal it that we’re friends: wear a smile, we talk.

MILES O’BRIEN: Arms open, whatever.

KARLEN LYONS-RUTH: To approach silently is threatening. The lab assistant leaves. So she then goes to mother, and then…see the mom step back? And the baby is now going to stop.

MILES O’BRIEN: She’s just comforting herself on the rug.

KARLEN LYONS-RUTH: She gets up, she looks to Mom, and she’s not quite comfortable just scooping her up, and she hesitates, and she does that and then she picks her up.

We call this the hot potato: pick up, put down. Quickly, the mom puts her down again in the middle of all the toys.

MILES O’BRIEN: Though this behavior would never qualify as abuse, some of the moms found it harder to comfort their distressed babies.

KARLEN LYONS-RUTH: As an observer, you see that there’s a bigger picture emerging. There’s the silent entry. There’s the not moving to the baby. There’s the hesitating when the baby moves to her. There’s the awkward pickup. There’s the quick put down. There’s the silent interaction from there on. So, as these accumulate, you begin to get much more pattern of the emptiness and what the baby is not getting in terms of regulating their own state.

MILES O’BRIEN: The research team has followed about 60 families over 30 years. Although there is not just one way to build attachment, certain patterns became clear. They found that the babies who had trouble calming down were more likely to grow up with behavioral problems once they go to school.


KARLEN LYONS–RUTH: They’re predicting that these were kids who are going to go on to have serious hostile and aggressive behaviors toward their classmates, even though they don’t look that way in infancy.

MILES O’BRIEN: And when they became adults, the same group was twice as likely to be anti-social or suicidal.

MOM WITH BOY: (Reading) And the pirate captain was…

MILES O’BRIEN: It’s not just the relationship with mothers that can count, but other caring relationships as well. And it’s not just the infant brain that can be altered by stress. Throughout childhood and adolescence, the growing brain is extremely sensitive to threatening situations.

MARTIN TEICHER (Harvard Medical School): When you’re exposed to stress, you program your body to have a more elaborate, greater stress response, and that can help you survive.

MILES O’BRIEN: Martin Teicher studies the effects of neglect, abuse and stressful environments on brain anatomy and function. He’s found that as a child grows up, different areas of the brain are more vulnerable, depending on age. And one of the most sensitive periods of all is the teenage years.

MARTIN TEICHER: It’s a period of very rapid transition. In that, that period between the onset of puberty and what we define, arbitrarily, as adulthood, say 18 or so, there’s a tremendous amount of brain change. There’s more brain change taking place in that period than will occur for the rest of your life.

MILES O’BRIEN: And a quickly changing brain is more likely to be altered and shaped by stress, potentially making it more prone to anxiety, depression, antisocial behavior and even violence. For example, the prefrontal cortex, responsible for higher-level thinking, can be stunted by stress and abuse during this period, making it even harder for teens to control their emotions.

So, could the pressures and strain prove too much to bear for those few teenagers who go on to become rampage killers?

To watch the video in its entirety, go to