A person's morality 'is influenced by evolving brain'

A team at the University of Chicago has found that a person's responses to similar situations change as they age, which is because of the evolving brain circuitry, the latest edition of the 'Cerebral Cortex' journal reported.

In their study, researchers combined brain scanning, eye-tracking and behavioural measures to understand how the brain responds to morally laden scenarios.

According to them, the study provides strong evidence that moral reasoning involves a complex integration between affective and cognitive processes that gradually changes with a person's age.

"Both preschool children and adults distinguish between damage done either intentionally or accidentally when assessing whether a perpetrator had done something wrong.

"Nonetheless, adults are much less likely than children to think someone should be punished for damaging an object, especially if the action was accidental," said lead researcher Jean Decety.

The different responses correlate with the various stages of development, Decety said, as the brain becomes better equipped to make reasoned judgements and integrate an understanding of the mental states of others with the outcome of their actions.

"Negative emotions alert people to the moral nature of a situation by bringing on discomfort that can precede moral judgement, and such an emotional response is stronger in young children," he explained.

For the research, the scientists studied 127 participants, aged 4 to 36, who were shown short video clips while undergoing an fMRI scan. The team also measured changes in the dilation of the people's pupils as they watched clips.

The participants watched a total of 96 clips that portrayed intentional harm, such as someone being shoved, and accidental harm, such as someone being struck accidentally, such as a golf player swinging a club.

Eye tracking in the scanner revealed that all of the participants, irrespective of their age, paid more attention to people being harmed and to objects being damaged than they did to the perpetrators.

The study revealed that the extent of activation in different areas of the brain as participants were exposed to the morally laden videos changed with age.

For young children, the amygdala, which is associated the generation of emotional responses to a social situation, was much more activated. But, adults' responses were highest in dorsolateral and ventromedial prefrontal cortex -- areas of the brain that allow people to reflect on the values linked to outcomes and actions.