As workers try to advance through the corporate world, they often hear the old adage, "It's not what you know, it's who you know." As a result, these workers are encouraged to attend happy hour functions with the office, avoid eating lunch alone at their desks and chat up the boss if they're alone with him or her in the elevator. Even the most technically proficient employees will likely be passed over for that promotion if they can't work well in small groups or lead a meeting of fellow staff. Those who do manage to get ahead likely possess emotional intelligence, a measure of how well a person can regulate his or her own emotions, as well as the emotions of other people. Emotional intelligence includes attributes such as empathy and emotional control.

The term "emotional intelligence" became famous when it served as the title of Daniel Goleman's 1995 book; the book featured a scintillating subtitle that promised to explain "why [emotional intelligence] can matter more than IQ." An IQ score, a number comprised of verbal, mathematical, mechanical and memory ability, can seem like the holy grail for intelligence, and it can remain an excellent predictor of how well a person will do in school. Yet Goleman's book served up examples of how poorly an IQ score can predict a person's earning power or eventual success and happiness in life. For that, Goleman argued, you had to turn to emotional intelligence and a person's ability to use his or her emotions to navigate the world. While IQ scores rely on a person's ability to identify one correct answer, life sometimes involves more than one right answer, as well as the ability to get along with more than one type of person.

Emotional intelligence has remained a sticky subject in the years since Goleman's book was published. For one, researchers still differ somewhat on a precise definition for emotional intelligence and how it can be measured (if it can be measured at all, some researchers would be quick to add). But at the same time that researchers grapple with what emotional intelligence means, they try to determine what it means for our brain. Could emotional intelligence be more than an indicator of future success? Might it also tell us how healthy our brain is overall? In this article, we'll take a look at the role emotional intelligence might play in predicting the likelihood of falling victim to depression, dementia and other brain disorders. Go to the next page for learn about the links between emotional intelligence and the brain.

Emotional Intelligence and the Brain

A person's IQ score has remained the gold standard in intelligence debates; it's the kind of number that goes on your permanent record. As a result, scientists have tried to use this little number as a way to ascertain the state of the brain. Take the case of dementia, in which memory fails and a person begins to lose the ability to remember simple facts and tasks. A decline in cognitive function, illustrated by a falling IQ score, has been used as a mean of predicting dementia.

However, this method has some failings, because people with very high IQs display the symptoms of dementia much later, and they score above predictive norms on cognitive tests. These people then decline much faster once they begin exhibiting symptoms because the disease has already progressed. Because they score so much higher than the norms, they miss out on valuable early intervention opportunities. Conversely, those with lower IQs have the potential to be misdiagnosed with dementia because they score below the cognitive norms [source: APA].

Because dementia usually includes an emotional component as well as these failings in memory, it may be useful to factor in someone's emotional intelligence during diagnosis. But how does emotion even factor into the brain? While many parts of the brain may be involved in regulating emotion, it really comes down to what's going on in the left and right hemispheres. The right side of the brain takes in the sensory information related to emotions and processes it. Then, that information is sent to the left side of the brain, which is responsible for language. The left side of the brain gives these emotions a name. Also central to the process are the cerebellum, amygdala and the corpus callosum, which transfers the information between the right and left hemispheres. While we may not know everything about emotional intelligence, it's reasonable to assume that a low level of it is due to a malfunction in one of these parts of the brain.

But can we use that knowledge to ascertain brain health? Not yet, since scientists still don't know exactly what causes many brain disorders. However, emotional intelligence may prove to be most valuable in terms of identifying and addressing risk factors. For example, smoking is a risk factor for many brain disorders, but a study conducted by a Barcelona university found that students with high emotional intelligence were less likely to consume tobacco or cannabis. These students seemed to be able to regulate their emotional state so that they were less tempted to use tobacco products, while those with lower emotional intelligence may be drawn to substance abuse to compensate for a poor emotional state.

Similarly, while a person with a high IQ may know the basics of nutrition, it may take an emotionally intelligent person to make the right food choices. In one study, researchers found that those with higher emotional intelligence were able to make better product choices in the store . The ability to select healthier products may protect the emotionally intelligent from the extremely dangerous risk factor of obesity.

Emotional intelligence has also been linked to better stress management and lower psychological distress, as well as lower rates of depression . When people are unable to recognize and control their emotions, they're more likely to have lower satisfaction with life. Does someone dissatisfied with life sound fun to be around? While it might sound obvious, emotionally intelligent people have better social networks to assist them should sickness occur; socializing may also help delay the onset of dementia. Because the emotionally intelligent get along with various types of people, they may also have a greater willingness to see a doctor and a greater likelihood of heeding the doctor's advice .

So there seem to be a few positive links between high emotional intelligence and brain health, but what happens when there's a lack of emotional intelligence? We'll find out if it has any brain effects on the next page.

Alexithymia and Lack of Emotional Intelligence

In 1991, Canadian psychologist Robert Hare released a study indicating that psychopaths may have different brains from the rest of us. While psychopaths remain intellectually aware of society's rules, they lack emotional intelligence. The profile of a psychopath includes impulsivity, lofty goals without the discipline or focus to achieve them, a propensity for boredom, no close personal attachments and of course, a lack of empathy. When Hare monitored psychopaths' brain waves while they examined certain words, including those that bring up a host of emotions for most people, he found that there was no activity in the parts of the brain involved in emotion. Hare described these psychopaths as "emotionally color-blind" to Maclean's magazine in 1996 .

Hare's work seems to indicate that psychopaths have abnormal brain functions in areas related to processing emotion and language -- meaning that there's a neurological rationale for some heinous crimes, as opposed to some environmental factor such as child abuse. If these psychopaths were to be tested for IQ, they would likely show up as normal, but it's in a lack of emotional intelligence that we see the disturbances in brain health.

If a person is on the low end of the emotional intelligence spectrum, he or she may have a condition known as alexithymia. Alexithymia is the inability to understand or express emotion. Because of what scientists know about emotions in the brain, they theorize that alexithymia may either relate to a malfunctioning in the right hemisphere or an overactive left hemisphere (leaving the right hemisphere unable to compensate). It's also possible that the corpus callosum, the part of the brain that governs communication between the right and left sides of the brain, is damaged to the point of blocking the messages regarding emotion .

Alexithymia sometimes manifests itself after a person suffers a brain injury such as blunt trauma. But the condition may eventually be able to tell us more about what happens during brain disorders absent of such trauma. For example, alexithymia has been linked to eating disorders, panic disorders and post-traumatic stress disorder. The condition may also provide clues about autism spectrum disorders one day; one common theme of autism disorders is a lack of emotional connection, so that those with the disorder can't pick up on social cues. Decreased cerebellum activity has been linked to autism and Asperger's disorder.

For more on emotional intelligence, IQ and other brainy topics, take a look at the links on the next page.

Hail to the Brain of the Chief

When Oliver Wendell Holmes met Franklin D. Roosevelt, he remarked that FDR demonstrated "a second-class intellect, but a first-class temperament" . This assessment speaks to Roosevelt's emotional intelligence.

Emotion may be an important factor in determining who's most fit for leadership. Fred I. Greenstein, a professor of politics at Princeton University, wrote a book evaluating 11 American presidents on six leadership qualities, including cognitive style and emotional intelligence. Greenstein found that Eisenhower, Ford, and George H.W. Bush were free of emotional conflicts that could have hampered their leadership, while Johnson, Carter, Nixon and Clinton had emotional handicaps that affected their presidencies . In Greenstein's view, Reagan, Truman, Kennedy and FDR faced emotional undercurrents that did not affect their leadership