New research performed at the University of Chicago suggests the human brain is able to detect within a split second whether a harmful action is intentional or accidental.

The research, performed by UChicago Professor Jean Decety and research associate Stephanie Cacioppo, was published in a paper, “The Speed of Morality: A High-Density Electrical Neuroimaging Study,” on Dec. 1 in the Journal of Neurophysiology.

According to a news summary:

The researchers studied adults who watched videos of people who suffered accidental harm (such as being hit with a golf club) and intentional harm (such as being struck with a baseball bat). While watching the videos, brain activity was collected with equipment that accurately maps responses in different regions of the brain and importantly, the timing between these regions. The technique is known as high-density, event-related potentials technology.

The intentional harm sequence produced a response in the brain almost instantly. The study showed that within 60 milliseconds, the right posterior superior temporal sulcus (also known as TPJ area), located in the back of the brain, was first activated, with different activity depending on whether the harm was intentional or accidental. It was followed in quick succession by the amygdala, often linked with emotion, and the ventromedial prefrontal cortex (180 milliseconds), the portion of the brain that plays a critical role in moral decision-making.

There was no such response in the amygdala and ventromedial prefrontal cortex when the harm was accidental.

This is interesting, but not entirely surprising. We already know that quick-firing emotional processes play a large role in shaping moral behavior. That’s just how the brain functions. If the human species slowly deliberated over the nature of every action and reaction, we probably would not have lasted too long as a species (you can read more on that here). As such, I think a more interesting question to ponder is how much of a role, if at all deliberate moral reasoning plays in shaping our quick-firing emotional processes. I’ll leave it to scientists to try and set up an experiment on that.