School Program Dampens Threat Response, Aggression

Elementary school program curbs hormone release, aggressive behavior in men.

Posted Apr 16, 2014

When sharing the world with other people, we get provoked sometimes. Learning to deal with it appropriately can keep you out of jail. A recent parking dispute in Dallas ended with one man shooting another in the leg.

According to a new study in Psychological Science, experiences during childhood affect how you handle angering encounters as an adult. We’ve known that risk factors for adult violence, such as bullying and a lack of concern when a peer gets hurt, pop up at a young age. Previous studies have shown that high-quality care can decrease the risk, but it wasn’t clear why.

Justin Carré from Nipissing University in Canada had a hunch it might have to do with testosterone, the hormone mainly produced in the testicles or ovaries. Males tend to have 8 times as much testosterone circulating compared to females.  Testosterone is released throughout the day, but levels can spike during conflict. Carré had seen in previous studies that men who release more testosterone following a provocation are more likely to resort to aggression; ice hockey players with higher testosterone levels spend more time in the penalty box.

In this study, Carré worked with developmental psychologist Kenneth Dodge from Duke University. Dodge helps oversee the Fast Track Project, a program that provided targeted help to young children with aggression and behavior problems.

In the early 1990’s, the Fast Track Project screened kindergarteners from several US locations, including Durham, North Carolina, for behavioral issues. They asked teachers and parents about aggressive and disruptive behavior and used the answers to rate each child. They identified around 900 children who, based on the teacher’s ratings, were above the 80th percentile for aggressive behavior relative to children their age.  Of those 900 children, about half received the intervention and the rest went to school as usual but didn’t get any special tutelage.

The parents of children in the intervention group received parenting training, including home visits. Several times a month during first through fifth grade, intervention students received two hour training sessions at school. During the sessions, tutors helped with reading skills and guided a playtime to help the child bond with classmates. In fifth and sixth grade, the tutors prepared the children for transitioning to middle school, leading discussion groups about alcohol, drugs and decision-making.

By 9th grade, benefits from the Fast Track intervention had already appeared. The children who received tutoring and mentoring had lower rates of attention deficit disorders and were less likely to have gotten in trouble with the law.

A few years ago, researchers invited men from the Fast Track study, now in their mid-twenties, to participate in a behavioral study at Duke University. 34 men from the intervention group, who received special mentoring and tutoring during elementary school, and 29 men from the control group, who were at risk for delinquency but received no special care, participated.

When they arrived at the laboratory, the men spit into a tube so their testosterone levels could be measured through their saliva. The researchers then gave them a chance to earn money playing a computer task. After the first task session, the men gave a second saliva sample and then did the task two more times.  

The researcher told them their computer was connected to someone else through the internet. They had three options, ‘A,’ ‘B’ or ‘C.’ Pressing the ‘A’ button earned them money, and they could see their total at the top of the screen. Sometimes, their earnings decreased. The researcher told them this meant the other person had pressed ‘B’ and stolen their money. The volunteer could press ‘B’ at any time to take money away from the other person, but they didn’t get to keep it. They could also press ‘C’ to protect their money from theft for about a minute. Stealing money by pressing ‘B’ was considered aggressive because the participant harmed the other person at no gain to himself.

The two groups showed different levels of aggressive behavior. Whereas the control group stole about two times for every time they had their money taken, the intervention group only stole one-and-a-half times. The control group increased their stealing rate in sessions two and three relative to session one, but the intervention group maintained their lower levels of stealing. All of these men showed early signs for delinquency in kindergarten, but those who received an intervention in elementary school were less aggressive adults than those who didn’t.  

The groups also had different testosterone changes following the first session. The groups had similar testosterone levels in their saliva before the first session. After the first session, the control group had a 7% increase. The intervention group, in contrast, showed a 6% decrease in testosterone in their saliva.

The change in testosterone predicted subsequent aggression. The men with bigger increases in testosterone after session one stole more money in sessions two and three. The authors found that testosterone response to the first session mediated the relationship between the intervention on aggressive behavior. If someone had a spike in testosterone after having his money stolen, he was more likely to retaliate.

Carré speculated that the Fast Track intervention may prevent aggression by normalizing how a person’s body responds during conflict. Feeling threatened may send a cascade of signals down from the brain that result in testosterone release. The spike in testosterone may propel someone to become unhinged when provoked. By helping regulate the biological response to provocation, the men who received special care in elementary school were able to remain calm.

Punishing a driver for stealing your parking place may seem enticing, but you may not want to make the news for losing your temper in a dispute at Macy’s. That realization may be important for peacefully resolving conflicts. Arriving at it, though, may require stable testosterone levels.

The evidence is convincing that we can curb violence with proper interventions, and now we have a better idea why. The question is, are we, as a society, willing to provide every child with the high quality care needed to achieve these benefits? I wish the answer was yes. 

Image credit: Guyon Morée