Having empathy means understanding and sharing another person's emotions, as opposed to singularly pursuing our own interests.
On September 13, 1848, in a railroad construction accident, an explosion drove an iron rod through the skull of Phineas Gage, a 25-year-old foreman.
The man survived and went on to live for another 12 years, but the accident reportedly turned him into a rude and inconsiderate person.
Here is how Gage's physician described the changes in his patient's behavior: "He is fitful, irreverent, indulging at times in the grossest profanity (which was not previously his custom), manifesting but little deference for his fellows, impatient of restraint of advice when it conflicts with his desires."
"In this regard, his mind was radically changed, so decidedly that his friends and acquaintances said he was 'no longer Gage,'" the doctor added.
Although the term "empathy" was not coined until 60 years later, the accident showed scientists that the ability to share another person's feelings has deep neurological roots.
In his book Zero Degrees of Empathy, Simon Baron-Cohen - a professor of developmental psychology at the University of Cambridge in the United Kingdom - explains how modern neuroscience has helped to illuminate that 19th-century case.
As Prof. Baron-Cohen explains, this is one of the 10 brain areas involved in the neural circuit "responsible" for creating empathy. By injuring a key element of this brain circuit, the accident deprived Gage of the ability to feel empathy.
So, can neuroscience help to explain why some of us are considerate toward our fellow human beings while others are not? If so, how? We take a look at some of the other brain regions that have been found to influence our ability to empathize.
The empathy brain circuit
A 3-D rendering of the skull of Phineas Gage, showing how the iron bar penetrated his vMPFC.
Image credit: Van Horn JD, Irimia A, Torgerson CM, Chambers MC, Kikinis R, et al.
In his book, Prof. Baron-Cohen walks us through the brain circuit involved in empathy. He says that there is neuroscientific consensus that empathy occurs across at least 10 brain areas, with more to be discovered.
As modern brain scanning technology has revealed, many of these same brain areas become activated not only when we experience a sensation or feeling ourselves, but also when we see other people experience it.
The first "stop" on the circuit is the medial prefrontal cortex (MPFC) - that is, the "social hub" of our brains. As Prof. Baron-Cohen explains, the dorsal MPFC has been shown to be involved in thinking about other people's thoughts and feelings as well as our own, while the ventral MPFC seems to be highly active when people think more about themselves than others.
The vMPFC may have other roles as well. Antonio Damasio, of the Department of Neurology at the University of Iowa College of Medicine in Iowa City, suggested that our vMPFC might act as an emotional bank that attaches and stores emotional valence to certain actions.
For instance, when confronted with violent or emotionally distressing images, the vMPFC is activated and causes physiological changes in the body, such as increasing the heart rate. But as Damasio shows, patients with injuries in this area are less responsive to such images in this way.
The vMPFC overlaps with the so-called orbitofrontal cortex. Prof. Baron-Cohen and his team were the first to show that people with injuries in this area have trouble telling when someone has committed a social faux pas or tend to become socially uninhibited - in much the same way that Phineas Gage did.
Next on the empathy circuit is the inferior frontal gyrus (IFG). Studies have shown that patients with damage in this area have trouble recognizing emotions on other people's faces.
Just like the IFG, the amygdala is also involved in recognizing facial expressions. A key part of our limbic system, the amygdala is essential to emotional learning, and a famous neurological case showed that damage to the amygdala can leave a patient without the ability to recognize fearful expressions.
Likewise, neurons in the caudal anterior cingulate cortex (cACC) have been shown by fMRI to "light up" when a person experiences pain, as well as when they see someone else in pain. The anterior insula is also activated under similar circumstances.
Both of these areas seem to enable us to put ourselves in another person's shoes, or as Dr. John Lewis puts it in the video below, to "model" another person's painful experience in our own heads.
The right tempoparietal junction (RTPJ), Prof. Baron-Cohen goes on to explain in his book, seems deeply involved with what philosophers have referred to as "the theory of mind" - that is, the process of attributing intentions to another person.
Interestingly, some experiments have shown that damage in this area can give people the strange, ghostly feeling that someone else is present in the room even when they are not.
Next to the RTPJ is the posterior superior temporal sulcus, which is a brain region that enables us to follow the direction of someone else's gaze. Another area key for empathy is the somatosensory cortex, which is also activated when someone sees another person in physical pain, as well as when we have a tactile experience ourselves.
Finally, our empathy would be impaired without our network of "mirror neurons." This consists of the IFG and the frontal operculum (located just above the IFG), which connect with the inferior parietal lobule (IPL) and the inferior parietal sulcus (situated behind the IPL).
Mirror neurons are brain cells that become activated when we mimic somebody else's actions. These are responsible for the "chameleon effect," or for the phenomenon of emotional contagion - be it involuntarily yawning or smiling when we see someone else smile.
Recent discoveries and unsolved puzzles
More recent findings complete the rich neuroscientific tapestry that explains why we care about other people. For example, Medical News Today have recently reported on a study that supports the idea that the ACC is key for the empathy circuit.
More specifically, the study shows that the so-called subgenual ACC is activated when people "learn" to perform generous acts.
Another study has shown that the right supramarginal gyrus helps to keep our selfishness in check. The brain area enables us to decouple our own interests and feelings from those of other people, and due to this region we are able to share somebody else's sadness even when we are happy with our own lives.
We have spoken a lot about brain areas that regulate empathy, but hormones also play a role. In a recent study reported by MNT, scientists found that oxytocin - popularly known as the "love" or the "attachment" hormone because we secrete it during physical contact with our loved ones - is crucial to our ability to empathize.
But despite all of this progress, much remains to be discovered. Speaking to MNT about this, Prof. Baron-Cohen said, "If you have two identical twins raised in the same environment, why should one of them have more empathy than another?"
"It could be differences in their social experience, including how the same parent(s) are treating each twin differently [...] or it could be epigenetic factors."
"We still know very little about individual differences in empathy. [...] We will need elegant experimental research to solve these puzzles."
Prof. Simon Baron-Cohen
What can we do to improve our empathy?
As history teaches us, insufficient empathy for those who differ from ourselves can sometimes lead to wars and even make us commit atrocities against our fellow human beings. This prompted Prof. Baron-Cohen to refer to empathy, in the video below, as "our most valuable resource for conflict resolution."
Although the "erosion of empathy" can make people treat their fellow humans in immensely cruel ways, the good news is that empathy is something that we can learn.
A recent study shows that just a few interactions with members of a group we typically perceive as "strange" or "other" can trigger a "learning effect" in the brain and increase the empathic response for those who seem different to us.
So, what are some other practical things that we can do to extend our empathy? For one thing, we can all read more novels; another recent study suggests that simply reading more fiction can excite our imagination to levels that can actually be observed in an fMRI machine, and that people who consistently read more fiction score much higher on empathy tests.
Speaking to MNT about what we can do to improve our empathy, Prof. Baron-Cohen suggests that empathizing could actually be taught in schools. He says, "[The] school curriculum typically doesn't include lessons in empathy but these could be tried."
"An example in Israel and Palestine is the remarkable Hand in Hand charity [...] where children are learning that there are other perspectives than their own, [...] that the 'enemy' is actually a person with feelings who may feel threatened too, and [...] that even if you disagree with someone you can do so gently or affectionately."
Prof. Simon Baron-Cohen