How your brain decides blame and punishment, and how it can be changed

Date:September 16, 2015

Source:Vanderbilt University

Summary:Juries in criminal cases typically decide if someone is guilty, then a judge determines a suitable level of punishment. New research confirms that these two separate assessments of guilt and punishment — though related — are calculated in different parts of the brain. In fact, researchers have found that they can disrupt and change one decision without affecting the other.

New work by researchers at Vanderbilt University and Harvard University confirms that a specific area of the brain, the dorsolateral prefrontal cortex, is crucial to punishment decisions. Researchers predicted and found that by altering brain activity in this brain area, they could change how subjects punished hypothetical defendants without changing the amount of blame placed on the defendants.

“We were able to significantly change the chain of decision-making and reduce punishment for crimes without affecting blameworthiness,” said René Marois, professor and chair of psychology at Vanderbilt and co-principal author of the study. “This strengthens evidence that the dorsolateral prefrontal cortex integrates information from other parts of the brain to determine punishment and shows a clear neural dissociation between punishment decisions and moral responsibility judgements.”

The research titled “From Blame to Punishment: Disrupting Prefrontal Cortex Activity Reveals Norm Enforcement Mechanisms” was published on Sept. 17 in the journal Neuron.

The Experiment

The researchers used repetitive transcranial magnetic stimulation (rTMS) on a specific area of the dorsolateral prefrontal cortex to briefly alter activity in this brain region and consequently change the amount of punishment a person doled out.

“Many studies show the integrative function of the dorsolateral prefrontal cortex in relatively simple cognitive tasks, and we believe that this relatively basic process forms the foundation for far more complex forms of behavior and decision-making, such as norm enforcement,” said lead author Joshua Buckholtz, now an assistant professor of psychology at Harvard.

The researchers conducted experiments with 66 volunteer men and women. Participants were asked to make punishment and blameworthiness decisions in a series of scenarios in which a suspect committed a crime. The scenarios varied by harm caused (ranging from property loss to grievous injury and death) and how culpable the suspect was for the act (fully responsible or not, due to mitigating circumstances.) Half of the subjects received active rTMS while the other half of the subjects received a sham or placebo version of rTMS.

Level of Harm

Across all participants and all trials, both culpability and level of harm were significant predictors of the amount of punishment the subjects deemed appropriate. But subjects receiving active rTMS chose significantly lower punishments for fully culpable suspects than did those subjects receiving sham rTMS, particularly in scenarios that resulted in low to moderate harm. Additional analyses suggested that the effect was due to impaired integration of signals for harm and culpability.

“Temporarily disrupting the dorsolateral prefrontal cortex function appears to alter how people use information about harm and culpability to render these decisions. In other words punishment requires that people balance these two influences, and the rTMS manipulation interfered with this balance, especially under conditions in which these factors are dissonant, such as when the intent is clear but the harm outcome is mild,” said Buckholtz.

Implications

The research team’s main goal in this work is to expand the knowledge of how the brain assesses and then integrates information relevant to guilt and punishment decisions. It will also advance the burgeoning interdisciplinary study of law and neuroscience.

“This research gives us deeper insights into how people make decisions relevant to law, and particularly how different parts of the brain contribute to decisions about crime and punishment. We hope that these insights will help to build a foundation for better understanding, and perhaps one day better combatting, decision-making biases in the legal system,” said co-author Owen Jones, professor of law and biological sciences at Vanderbilt and director of the MacArthur Foundation Research Network on Law and Neuroscience.


Story Source:

The above post is reprinted from materials provided by Vanderbilt University. The original item was written by Amy Wolf. Note: Materials may be edited for content and length.


Journal Reference:

  1. Joshua W. Buckholtz, Justin W. Martin, Michael T. Treadway, Katherine Jan, David H. Zald, Owen Jones, René Marois. From Blame to Punishment: Disrupting Prefrontal Cortex Activity Reveals Norm Enforcement Mechanisms. Neuron, 2015; DOI: 10.1016/j.neuron.2015.08.023
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Choice of college major influences lifetime earnings more than simply getting a degree

Date:September 16, 2015

Source:University of Kansas

Summary:A new study based on longitudinal data confirms a college degree provides an advantage in lifetimes earnings, but a related decision once students make it to college could prove to be even more crucial as STEM majors earn roughly $700,000 more over 40 years than social science or humanities majors.

The study that includes a University of Kansas researcher found large lifetime earnings gaps depending on a student’s field of study. For examples, men who major in science, technology, engineering and mathematics, or STEM fields, and earning a bachelor’s degree achieved roughly $700,000 to $800,000 higher 40-year lifetime earnings from ages 20 to 59 than social science or liberal arts majors.

“That means the decision for whether for you going to college versus what kind of major you want to study, the latter decision is more important for your lifetime earnings,” said Kim, a KU associate professor of sociology and the study’s lead author.

Social science or liberal arts majors with a bachelor’s degree in social science or liberal arts majors still earn $400,000 more than high school graduates, but gaining an advanced degree in social science does not raise lifetime earnings substantially compared to a bachelor’s degree in the same major, the study found.

Kim said the study is meant to show the labor-market differentials across field of study because there is little research right now in this area. However, the researchers don’t dispute there are other benefits to earning a liberal arts or humanities degree.

“When you are educated, you have a better lifestyle. You can maybe enjoy more complicated books, so you have more engaging or more interesting conversations with value,” Kim said. “There is a whole other benefit of education. A liberal arts education is good, but it doesn’t necessarily transform into a high salary.”

Surprisingly, men who have a college degree in an education major earn only $46,000 over 40 years compared to high school graduates. When a 4 percent annual discount rate is applied for future earnings, the lifetime value of college degree for some majors compared to a high school degree turns out to be slightly negative.

The journal Sociology of Education recently published the article “Field of Study in College and Lifetime Earnings in the United States” online, and the study will appear in the October edition of the journal Sociology of Education.

This is the first study to use nationally representative survey data matched to longitudinal earnings data spanning a long stretch of the same person’s life to document how lifetime earnings vary by field of study and how lifetime earnings change by getting an advanced degree in different fields. Past studies had relied on either one year or a limited number of years of data with projections and did not estimate the effect of field of study on lifetime earnings for those who have an advanced degree.

The researchers examined Social Security Administration personal income tax data to follow the earnings of the same individuals over 20 years and then estimated the long-term effects of fields of study for U.S. men and women. The study included three measures of lifetime earnings: gross lifetime earnings by majors; net lifetime earnings after accounting for demographic and high school performance related factors; and net present value at age 20 after applying a 4 percent discount rate.

Kim said the overall findings likely aren’t surprising because engineering and professional jobs that require STEM or business degrees do gain higher economic returns in the open market. However, he said the degree of difference in earnings suggested the horizontal stratification in education across field of study appears to be more consequential than the usual focus on vertical stratification, which refers to the earnings gap between levels of education.

For one, it illuminates the importance of foregoing some earnings, especially in your 20s while attending graduate school, especially for students in majors that wouldn’t typically earn high returns over their lifetime. Attending graduate school in the social sciences or liberal arts added much less earnings than a graduate student in a professional field, for example.

“The reason why going to graduate school is not going to be very beneficial for some majors in terms of financing is to get the degree you need to spend your time in school for an extended period of time. That’s time you’re not going to be working. Even though you earn more after getting a degree, it is not enough to substantially raise your lifetime earnings,” Kim said.

However, the findings could be key in two other areas: examining the effects of gender on earnings and economic inequality.

Related to gender, college degrees no matter the field of study seem to benefit women with higher earnings compared with women who only graduated high school. For men in some fields of study, the earnings return would not be as high as a woman over her high school counterparts.

“This is not because college-educated women earn more than equally educated men,” Kim said, “but because labor market opportunities for less educated women are so scarce.”

Also, other studies have found that students from less-educated families tend to flock more to STEM fields or others with higher earnings returns than students of educated parents, who might be more inclined to choose a liberal arts degree.

“This kind of major choice we have is one mechanism to actually reduce economic inequality,” he said.


Story Source:

The above post is reprinted from materials provided by University of Kansas. Note: Materials may be edited for content and length.


Journal Reference:

  1. C. Kim, C. R. Tamborini, A. Sakamoto. Field of Study in College and Lifetime Earnings in the United States. Sociology of Education, 2015; DOI: 10.1177/0038040715602132

Fearless fowl grow and lay better

Animal populations that humans selected to domesticate grew increasingly tame

Date:
September 16, 2015
Source:
Linköping University
Summary:
A reduced fear of humans can be the driving force behind the characteristics that have developed since wild animals became domesticated, according to research by ethologists.

About 8,000 years ago we began to domesticate animals — a process that fundamentally changed the way animals and people live. Domesticated animals of today have characteristics that distinguish them from their wild ancestors, including size, colour, reproduction and behaviour.

In a fresh study the LiU researchers show that many of these changes can have been driven by a simple fact: the animal populations that humans selected to domesticate grew increasingly tame. The study is now published in Biology Letters.

The researchers used a population of red junglefowl (Gallus gallus), the wild ancestor of all domesticated fowl. For five generations they selected animals with a congenital reduced fear of humans, and bred their offspring. For comparison, they also bred a separate line from the fowl that were most fearful of humans.

“We used a standardised behaviour test where we studied the fowl’s reaction to a human. This method resembled the conditions during the very first stage of fowl husbandry 8,000 years ago,” says Beatrix Agnvall, doctoral student in ethology and first author of the article.

After just five generations, the increasingly tame fowl had developed a higher metabolism and feed conversion rate — they grew more although they ate less than the more fearful animals in the control group. They were also more cautious in situations where humans were not involved, and, as in previous studies of the same animals, they laid larger eggs. The levels of the hormone serotonin were higher in the tame roosters, and the researchers believe that this can be one of the mechanisms driving the results.

According to Per Jensen, professor of ethology at LiU and head of the study, increased tameness was an important prerequisite in the animals’ ability to live with humans.

“The results show that it can automatically have led to many of the characteristics that we and our ancestors liked about domesticated animals. Therefore we can suppose that our ancestors didn’t necessarily select animals because they were good at producing food, but mainly because they were easy to manage,” says Prof Jensen, who believes the results could also apply to other domesticated animals like pigs, sheep and cattle.


Story Source:

The above post is reprinted from materials provided by Linköping University. Note: Materials may be edited for content and length.


Journal Reference:

  1. B Agnvall, R Katajamaa, J Altimiras & P Jensen. Is domestication driven by reduced fear of humans? Boldness, metabolism and serotonin levels in divergently selected red junglefowl (Gallus gallus). Biology Letters, September 2015 DOI: 10.1098/rsbl.2015.0509