Whether we condemn the villain in a movie or feel that somebody has wronged us personally, many of us make moral judgments on a daily basis. From a neuropsychological viewpoint, the act of judging a moral situation is incredibly complex and has a lot to do with intentionality – did the perpetrator really mean to do those awful things? What happens in our brain when we know that whoever caused the harm did so unintentionally? New research investigates the neuroanatomical basis of forgiveness.

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A new study shows that a specific area in the brain plays a key role in forgiving unintentional harm.

The new study examines the role of a brain area called the anterior superior temporal sulcus (aSTS) in forgiving those who make unintentional mistakes.

The researchers were led by Giorgia Silani from the University of Vienna in Austria, and the study was carried out in collaboration with scientists from Trieste University in Italy and Boston College in Massachusetts. The findings were recently published in the journal Scientific Reports.

As the authors explain, making a mature moral judgment about a wrongful act involves not only considering the damage done, but also the perpetrator’s intention and mental state. When there is a clear contradiction between the two, however, intention seems to take precedence over the result of the action.

Indrajeet Patil, the study’s primary author, details this further and puts the new research into context:

“Behavioural studies have already shown that when the intention and outcome of an action are conflicting, as in the case of sometimes serious accidental harm, people tend to focus mainly on the intentions when formulating a judgment. And this is more or less a universal feature of mature moral judgments across cultures,” Patil explains.

“To date, however, very few studies have taken on this issue from an anatomical point of view, to gain an understanding of whether differences in the volume and structure of certain areas of the brain might explain variations in moral judgment. This research attempted to explore precisely this aspect.”

To do this, the researchers asked 50 participants to complete a moral judgement task. The volunteers were presented with 36 unique stories and four potential outcomes for each of them.

Each scenario comprised four parts: some background information; a so-called foreshadowing segment, in which it was suggested that the outcome would be either neutral or harmful; information on the neutral or intentionally harmful mental state of the agent; and, finally, the consequence, which revealed the agent’s action and the resulting outcome.

Participants read each story and were asked to give their moral judgment by answering questions regarding “acceptability” and “blame.” Namely, the participants were asked: “How morally acceptable was [the agent]’s behavior?” and “How much blame does [the agent] deserve?” The volunteers gave answers based on a scale from 1 to 7.

While answering the questions, the participants’ brain activity was analyzed using voxel-based morphometry – a neuroimaging technique that allows for a holistic examination of brain changes while simultaneously preserving a high degree of brain region specificity.

The researchers also used neuroimaging to localize the neural areas responsible for the so-called theory of mind (ToM). ToM, or “mentalizing,” is a person’s ability to correctly attribute mental states – such as beliefs, intentions, and desires – to others based on their behavior. Mentalizing also refers to the person’s ability to explain and predict other people’s behavior based on these inferences.

The results revealed a connection between the differences in moral judgement severity about unintentional harm and the volume of the left aSTS brain region.

More specifically, the more developed the aSTS was, the less blame was attributed to the wrongdoers. “The greater the gray matter volume [in this area], the less accidental harm-doers are condemned,” the authors write.

Patil further explains the findings:

The aSTS was already known to be involved in the ability to represent the mental states (thoughts, beliefs, desires, etc.) of others. According to our conclusions, individuals with more gray matter at aSTS are better able to represent the mental state of those responsible for actions and thus comprehend the unintentional nature of the harm. In expressing judgment they are thus able to focus on this latter aspect and give it priority over the especially unpleasant consequences of the action. For this reason, ultimately, they are less inclined to condemn it severely.”

This study opens up new avenues for neuroscientific research. Patil and colleagues recommend that further studies use more realistic contexts to study moral judgments, as well as using a more demographically diverse study sample.

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