Testosterone leads to dog abuse.
Robert Josephs, associate professor of psychology, and Amanda Jones, graduate student, examined how testosterone levels influence pet owners’ behavior and, in turn, how they affect the hormonal changes in their animals during stressful situations.
Their findings appear in a paper titled “Interspecies Hormonal Interactions Between Man and the Domestic Dog” in the current issue of Hormones and Behavior, a biology journal.
The researchers found men’s testosterone levels determined their behavior toward their dogs, after the dogs performed poorly in a statewide agility competition. Men with high levels of testosterone punished their dogs by hitting them and yelling at them whereas men with lower levels supported their dogs by petting and praising the losing animals.
The response of these men is probably counterproductive. The abuse causes brain damage that inhibits memory formation. Therefore learning is impaired and the dogs become less likely to learn the lessons they need to excel.
Punished dogs showed an alarming rise in the stress hormone cortisol, a neurotoxic substance that can lead to destruction of cells in the hippocampus, leading to memory deficits. Chronically elevated cortisol levels also weaken the immune system. These consequences might be especially critical for dogs in high stress jobs in which memory and health are critical, such as bomb-sniffing, police and guide dog environments.
Although there is much research demonstrating how changes in an individual’s hormone levels influence behavior toward another individual of the same species, this is the first research to examine effects across the species boundary.
I've had a couple of bosses who suffered from testosterone toxicity. They also exerted counterproductive effects on the workplace. Competitiveness and drive help to a point. But these drives have to be coupled to strong discipline and a considerable amount of wisdom or else the aggressiveness just destroys.
Anyway, I feel sorry for these abused dogs. Guys who hit a dog for failing to do well in agility training ought to go find a sport that forces them to perform rather than torture dogs into performing.
When genetic engineering of offspring becomes possible will the average male baby get genetically engineered to have higher or lower testosterone than happens now naturally? Will parents want to have assertive, athletic, and dominant sons and therefore opt for more testosterone?
We live among lots of dangerous people.
A little-known mental disorder marked by episodes of unwarranted anger is more common than previously thought, a study funded by the National Institutes of Health's (NIH) National Institute of Mental Health (NIMH) has found. Depending upon how broadly it's defined, intermittent explosive disorder (IED) affects as many as 7.3 percent of adults — 11.5-16 million Americans — in their lifetimes. The study is based on data from the National Comorbidity Survey Replication, a nationally representative, face-to-face household survey of 9,282 U.S. adults, conducted in 2001-2003.
I bet these people with IED will eventually be identifiable with brain scans. Suppose a treatment to stop IED is developed. Will future societies support mandatory delivery of therapies that prevent violent episodes?
People with IED have other mental problems.
People with IED may attack others and their possessions, causing bodily injury and property damage. Typically beginning in the early teens, the disorder often precedes — and may predispose for — later depression, anxiety and substance abuse disorders. Nearly 82 percent of those with IED also had one of these other disorders, yet only 28.8 percent ever received treatment for their anger, report Ronald Kessler, Ph.D., Harvard Medical School, and colleagues. In the June, 2006 Archives of General Psychiatry, they suggest that treating anger early might prevent some of these co-occurring disorders from developing.
To be diagnosed with IED, an individual must have had three episodes of impulsive aggressiveness "grossly out of proportion to any precipitating psychosocial stressor," at any time in their life, according to the standard psychiatric diagnostic manual. The person must have "all of a sudden lost control and broke or smashed something worth more than a few dollars…hit or tried to hurt someone…or threatened to hit or hurt someone."
People who had three such episodes within the space of one year — a more narrowly defined subgroup — were found to have a much more persistent and severe disorder, particularly if they attacked both people and property. The latter group caused 3.5 times more property damage than other violent IED sub-groups. Affecting nearly 4 percent of adults within any given year — 5.9-8.5 million Americans — the disorder leads to a mean of 43 attacks over the course of a lifetime and is associated with substantial functional impairment.
Evidence suggests that IED might predispose toward depression, anxiety, alcohol and drug abuse disorders by increasing stressful life experiences, such as financial difficulties and divorce
Once we achieve the ability to reverse aging using SENS techniques the existence of people who are capable of explosive anger and physical attacks will be viewed as a much bigger threat due to the length of individual lives. A person who goes overboard in their reactions when they get angry is more likely to kill someone if they have centuries more to do so. If we live for thousands of years each of us will face a much larger risk of eventually getting murdered.
In an era when aging becomes fully reversible I expect we will witness movements to create new nations that have extremely selective immigration policies designed to keep out people with violent tendencies. New polities will be created by long livers who want to minimize their risk of death. Such polities will also implement very high safety standards.
Higher prenatal testosterone has already been found to be correlated with a higher ratio of ring finger length to index finger length. Now University of Alberta researchers Peter Hurd and Allison Bailey have shown that the higher ring finger to index finger ratio is correlated with physically aggressive behavior in men.
Dr. Peter Hurd initially thought the idea was "a pile of hooey", but he changed his mind when he saw the data.
Hurd and his graduate student Allison Bailey have shown that a man's index finger length relative to ring finger length can predict how inclined that man is to be physically aggressive. Women do not show a similar effect.
A psychologist at the University of Alberta, Hurd said that it has been known for more than a century that the length of the index finger relative to the ring finger differs between men and women. More recently, researchers have found a direct correlation between finger lengths and the amount of testosterone that a fetus is exposed to in the womb. The shorter the index finger relative to the ring finger, the higher the amount of prenatal testosterone, and--as Hurd and Bailey have now shown--the more likely he will be physically aggressive throughout his life.
"More than anything, I think the findings reinforce and underline that a large part of our personalities and our traits are determined while we're still in the womb," said Hurd.
Hurd and Bailey's research, published this March in Biological Psychology, was determined from surveys and hand measurements of 300 U of A undergraduates.
In their study, they found there were no correlations between finger lengths and people who are prone to exhibit verbally aggressive, angry, or hostile behaviors, but there was to physically aggressive behavior.
Hurd is conducting ongoing research in this area, including a study that involves measuring hockey players' finger lengths and cross referencing the results with each player's penalty minutes. He also has a similar study showing that men with more feminine finger ratios are more prone to depression; a paper on this will be published later this year in Personality and Individual Differences.
"Finger lengths explain about five per cent of the variation in these personality measures, so research like this won't allow you to draw conclusions about specific people. For example, you wouldn't want to screen people for certain jobs based on their finger lengths," Hurd said. "But finger length can you tell you a little bit about where personality comes from, and that's what we are continuing to explore."
Every year that goes by more of human behavior is going to be pinned down to biological causes. Mechanisms of operation of each cause will be worked out down at the molecular level. This is going to be quite the challenge to mainstream Western liberal thought and to at least some schools of Christian theology (though perhaps not to those who believe in predestination) as the ghost is shown to have progressively less operating leeway within the machine.
Are you a male that is worried you have too much testosterone that is making you too aggressive? Get married and have kids and your blood testosterone will go down. On the other hand, if you want that aggressive edge and really good visual-spatial abilities then either eschew marriage or wear a testosterone patch. Not that I'm advocating hormone dosing...
WASHINGTON -- Scientists may be learning why it's so hard to stop the cycle of violence. The answer may lie in the nervous system. There appears to be a fast, mutual, positive feedback loop between stress hormones and a brain-based aggression-control center in rats, whose neurophysiology is similar to ours. It may explain why, under stress, humans are so quick to lash out and find it hard to cool down. The findings, which could point to better ways to prevent pathological violence, appear in the October issue of Behavioral Neuroscience, which is published by the American Psychological Association (APA).
In five experiments using 53 male rats, behavioral neuroscientists from the Netherlands and Hungary studied whether stimulating the brain's aggression mechanism raised blood levels of a stress hormone and whether higher levels of the same hormone led to the kind of aggression elicited by that mechanism. The results showed a fast-acting feedback loop; the mechanism works in both directions and raising one variable raises the other. Thus, stress and aggression may be mutually reinforcing, which could explain not only why something like the stress of traffic jams leads to road rage, but also why raging triggers an ongoing stress reaction that makes it hard to stop.
In the study, the scientists electrically stimulated an aggression-related part of the rat hypothalamus, a mid-brain area associated with emotion. The rats suddenly released the stress hormone corticosterone (very like cortisol, which humans release under stress) -- even without another rat present. Normally, rats don't respond like that unless they face an opponent or another severe stressor.
Says lead author Menno Kruk, PhD, "It is well known that these stress hormones, in part by mobilizing energy reserves, prepare the physiology of the body to fight or flee during stress. Now it appears that the very same hormones 'talk back' to the brain in order to facilitate fighting."
To study the hypothesized feedback loop from the other direction, the scientists removed the rats' adrenal glands to prevent any natural release of corticosterone. Then researchers injected the rats with corticosterone. Within minutes of injection, the hormone facilitated stimulation-evoked attack behavior.
Thus, in rapid order, stimulating the hypothalamic attack area led to higher stress hormones and higher stress hormones led to aggression – evidence of the feedback loop within a single conflict. Write the authors, "Such a mutual facilitation may contribute to the precipitation and escalation of violent behavior under stressful conditions."
They add that the resulting vicious cycle "would explain why aggressive behavior escalates so easily and is so difficult to stop once it has started, especially because corticosteroids rapidly pass through the blood-brain barrier." The findings suggest that even when stress hormones spike for reasons not related to fighting, they may lower attack thresholds enough to precipitate violent behavior. That argument, if extended in research to humans, could ultimately explain on the biological level why a bad day at the office could prime someone for nighttime violence toward family members.
Stress reaction is one of the evolutionary legacies of human evolution that in modern conditions is mostly maladaptive. Most people who get angry or frustrated and therefore feel stress are not benefitting and are even being harmed by the stress. We need better biotechnological tools for suppressing stress response. This would do more than reduce the incidence of acts of violence. Heart disease, general aging, depression, and other maladies would occur less frequently if stress responses happened less often.
Regarding my previous post on car cruise controls and automated driving: One of the benefits of being able to turn driving over to computers would be a reduction in feelings of stress. The stress of fighting commuter traffic comes on top of stresses associated with work and home life. Lower levels of stress made possible by automated driving computers would reduce both illness and violence.
Beware people with uneven body shapes.
Research showed that the farther certain paired body parts were from symmetry – if one ear, index finger or foot was bigger than another, for example – the more likely it is was that a person would show signs of aggression when provoked. The symmetry effects were different in men and women, however.
While the findings may seem strange, there is a plausible explanation, said Zeynep Benderlioglu, co-author of the study and a post-doctoral researcher at Ohio State University.
The physical attraction people have to highly symmetrical faces in the opposite sex is very likely the product of natural selection. The symmetry is a sign of health and reproductive fitness. This latest study shows that asymmetry is even a proxy for a tendency toward impulsiveness.
Body asymmetry is thought to be an indicator that the fetus was under stress (e.g. toxins, nutrient deficiencies or perhaps more stress hormones released by the mother) during development. The visible physical asymmetry is thought to be a proxy for malformations of other less visble parts of the body including the brain.
The study involved 100 college students (51 men and 49 women). Researchers measured differences in size of several paired body parts, including finger length, palm height, wrist diameter, elbow width, ear height and width, foot breadth and ankle circumference. The sum of all the differences in these pairs gave researchers a score of asymmetry for each participant.
The students, who were all volunteers, were told they were going to participate in a study of persuasive ability. They were given a list of phone numbers to call and attempt to raise funds for a fictitious charity organization. But they were actually calling two people involved in the study who were given instructions about how to respond to the study participants.
One of the people the participants called seemed friendly and amenable to giving, but said he didn’t have money to donate. But the second charity target was confrontational. He directly challenged the caller and the worthiness of the donation.
The researchers had rigged the phones so they could measure how hard the participants slammed the receiver down after the call – this was a measure of reactive aggression.
Results showed that, in general, the more asymmetry the participants showed in their body parts, the more force they used when hanging up the phone.
But there were also interesting gender differences.
In men, asymmetry was related to a more aggressive response when ending the phone call under the low-provocation condition – when the person simply didn’t have money to give. But there was no such association between asymmetry and aggression in the high-provocation condition -- when they talked with the rude charity target.
For women, it was just the opposite – there was no relation between asymmetry and aggression with the low-provocation caller, but women with higher asymmetry scores used more force when hanging up from the rude, high-provocation caller.
Benderlioglu said these results probably have to do with the different ways men and women respond to provocation in general.
“Research has shown that men are quicker to anger than are women,” she said. “But while unprovoked men are generally more aggressive than women, the gender differences either disappear under provocation, or women may actually become more aggressive than men.”
High testosterone made men more angry during low-provocation phone calls. But the opposite was the case with women.
Men with high levels of testosterone used more force when slamming down the phone only under the low-provocation condition. In women, higher levels of testosterone were associated with higher aggressiveness only under the high-provocation condition.
One of the most interesting twists is that confrontational behavior does not always elicit an aggressive response. But this makes sense intuitively. In many situations a person who shows fear is more likely to be attacked than a person who acts menacingly.
Update: Also see my related post Premature Birth Produces More Lasting Brain Effects In Boys. Factors that cause less than optimal conditions during pregnancies have the potential of creating behavior problems that will endure for life. Drug abuse, malnutrition, physical abuse of pregnant women, and other stressors on developing fetuses exact a very long term cost to society as a whole.
People have the concept that soy is only beneficial, said Jay R. Kaplan, Ph.D., professor of comparative medicine and anthropology, one of the investigators. "There is the thought that what is good for some is good for all and more is better."
But this research points out that not only does the dose make a difference, but so does the sex of the consumer, Kaplan said, adding that the study is consistent with emerging literature showing that soy can have a negative impact on the behavior of male rodents. Previous studies have shown no difference in aggression in females given large doses of soy, Kaplan said.
The study was done over 15 months with adult male monkeys who were divided into three groups and fed different amounts and types of protein. One group had about 125 mg of isoflavones a day. The second group had half that amount, and the third group's protein came from milk and animal sources.
"In the monkeys fed the higher amounts of isoflavones, frequencies of intense aggressive and submissive behavior were elevated," according to the study. "In addition, the proportion of time spent by these monkeys in physical contact with other monkeys was reduced by 68 percent, time spent in proximity to other monkeys was reduced 50 percent and time spent alone was increased 30 percent."
Isoflavone levels of 125 mg per day are higher than amounts consumed by many Asians, who typically eat more soy than other populations. But, the isoflavone levels are comparable to levels found in many dietary supplements sold in the United States.
The fact that it increases both aggressive and submissive behavior is curious. Did it increase aggression in some monkeys and submission in others? Or was it a function of circumstance with the same monkeys showing more of each behavior?
Steroid use by athletes causes violent outbursts popularly known as "roid rage". Does the combination of soy and steroids act synergistically to produce even more violent behavior?
Will gang members or other deviants start using isoflavones in order to make themselves more aggressive?
An excellent article by Erin Anderssen and Anne McIlroy in the Canadian Globe And Mail summarizes research on child development and human violence. They report that Richard Tremblay has found that 2 year old babies are more physically aggressive than teenagers or adults but fortunately too uncoordinated to do much damage to others.
Are human beings born pure, as Rousseau argued, and tainted by the world around them? Or do babies arrive bad, as St. Augustine wrote, and learn, for their own good, how to behave in society?
Richard Tremblay, an affable researcher at the University of Montreal who is considered one of the world leaders in aggression studies, sides with St. Augustine, whom he is fond of quoting. Dr. Tremblay has thousands of research subjects, many studied over decades, to back him up: Aggressive behaviour, except in the rarest circumstances, is not acquired from life experience. It is a remnant of our evolutionary struggle to survive, a force we learn, with time and careful teaching, to master. And as if by some ideal plan, human beings are at their worst when they are at their weakest.
St. Augustine was obviously much closer to the truth.
What Dr. Tremblay and his colleagues around the world have now demonstrated is that the ability to feel rage exists the moment human beings take their first breaths. A four-month-old infant can show anger. And as they gain more control over their arms and legs, their mothers report increasing incidents of kicking and biting: They can also act in anger.
By the second year, aggressive behaviour peaks in temper tantrums, with slapping and pushing; according to Dr. Tremblay's work, a typical two-year-old, playing with others over the course of an hour, will commit one act of physical aggression for every four social interactions.
With teenagers, he says, researchers talk in terms of years or months or weeks between aggressive acts -- never hours -- though the incidents, obviously, are more severe. By their third birthdays, children have the motor skills to perform any of the acts of aggression an adult can. But at just that age, aggression begins to drop.
For almost everyone, it continues to drop for the rest of their lives. By Dr. Tremblay's calculation, only in about 5 per cent of men does the rate of aggression remain relatively stable into early adulthood. They are the most dangerous group to society.
The article tries to put what I consider to be an excessive environmental spin on the reason for the decline in physical aggression as children age. The fact that babies simultaneously become more physically coordinated and less violent at the same time strikes me as too much of a coincidence to be the result of teaching and discipline. Likely there is a genetically programmed stage of mental development that builds inhibiting neural circuits to control the physical outbursts.
The article vaguely refers to a study on the genetic and environmental factors that cause children to grow up to be antisocial. That is probably a reference to a New Zealand twins study which showed that a combination of a genetic variant for low level of expression of Mono-Amine Oxidase A (MAOA) and childhood abuse produces much higher rates of adolescent and adult criminal violence. However, contrary to Anderssen and McIlroy the study did not show that both the environmental and genetic factors studied had to be present to result in violence. It is just that those two factors made children far more prone to grow up to be violent. Some children who were not abused still grew up to be violent. Similarly, some children who expressed MAOA at a high level still grew up to be violent as well. There may be still more as yet unknown genetic variations, nutritional factors, toxins, social environmental factors, and other factors which contribute to higher probability of violent behavior.
The article also refers to Adrian Raine's work using positron emission tomography (PET) scans that showed differences in the glucose consumption rates in the brains of murderers.
For the Biological Psychiatry study, Dr. Raine directed scientists at USC and the University of California at Irvine as they used positron emission tomography (PET) to scan the brains of 41 murderers who had pleaded not guilty by reason of insanity. The scientists also scanned the brains of 41 control subjects matched for known mental disorders and for age and gender. Mental disorders among the subjects included schizophrenia, organic brain damage and a history of head injury.
PET scans measure the uptake of blood sugar (glucose) in various brain areas during the performance of simple, repetitive tasks. (Glucose is the basic fuel that powers most cell functions. The amount used is directly related to the amount of cell activity.)
On average, the murderers showed significantly lower rates of glucose uptake in three areas of the brain -- the prefrontal cortex, the corpus callosum and the posterior parietal cortex. Their rates were 4, 18 and 4 percentage points lower, respectively, than the rates measured in control subjects performing the same tasks.
When the researchers compared the brain's two hemispheres for glucose uptake rates, they found that murderers consistently showed weaker activity in the amygdala and the hippocampus of the brain's left -- or more rational -- hemisphere. These glucose uptake rates were each 4 percentage points lower than the rates measured in control subjects performing the same tasks.
But the murderers showed stronger activity in the thalamus, the amygdala, and the hippocampus of the right -- or more emotional -- hemisphere. These glucose uptake rates were 6, 6 and 3 percentage points higher, respectively, than the rates measured in control subjects performing the same tasks.
Raine has also shown that that psychopaths have distinct differences in the shapes of some parts of their brains and that violent criminals have less brain gray matter.
These discoveries add up to suggest that there are limits to how much violent tendencies can be reduced using environmental changes and different methods of teaching and disciplining children. It seems unlikely that methods of teaching and socialization can fully compensate for less grey matter in those who commit violent acts as adults or the larger corpus callosums and asymmetrical hypothalamuses found in psychopaths.