“Christina Taylor” (not her real name) recalled her early impressions of her husband of 18 years, “David,” as being emotionally steady. “I never saw any emotion, but I didn’t think much about it then, because he was so level-headed, and never angry,” says Christina, a 48-year-old science teacher in Michigan. “I just always thought he wasn’t good at sharing feelings or didn’t trust me enough — it has caused me to be frustrated at times in our marriage.”

But David was no ordinary stoic male. Christina only recently learned that his emotionless behavior and mechanical responses — which she often believed were her own fault — were instead the results of “alexithymia”: a personality trait describing people who lack the ability to illustrate and identify their emotions. First coined in 1972, by psychotherapist Dr. Peter Sifneos, alexithymia encompasses how individuals process and express their own emotions, and how people deal with others’ feelings.

Although it is not classified as a disorder in the Diagnostic and Statistical Manual of Mental Disorders, it is considered to be a personality trait that places individuals at risk for other medical and psychiatric disorders while reducing the likelihood that these individuals will respond to conventional treatments for their other conditions, according to research, titled “An Observer Scale to Measure Alexithymia” by Haviland, Warren, and Riggs, published in Psychosomatics Journal.

Studies have shown that somewhere between 4.7 percent and 8.9 percent of the population test high in alexithymia. These individuals are sometimes described as distant, logical, and cold. They prefer to discuss mundane day-to day events instead of how they feel, and are very uncomfortable with intimacy.

“They are more anxious regarding intimacy, instead preferring to stay somewhat distant in their relationships,” says Dr. Colin Hesse, a professor of communications at the University of Missouri, who has been researching the long-term effects of alexithymia in the realm of relationships. “People who know them commonly tell them that they are not in touch with their emotions.” Often, alexithymics lack imagination and creativity, and have trouble distinguishing emotional feelings from bodily feelings. For example, a person could confuse crying with a blocked tear duct, rather than recognizing their own feelings of sorrow.

According to Dr. H. Freyberger, a psychoanalyst who worked with Sifneos, alexithymia can be broken into two categories, secondary and primary. Secondary alexithymia usually occurs when a person has gone through a traumatic or horrifying experience and is often a temporary or transient condition; primary alexithymia is believed to be inherent in a personality.

“Alexithymia is conceived as a personality trait that we all have in various degrees,” says Hesse. “If an individual does not know that they are terrible at understanding and communicating emotions, and also does not understand how these emotional problems are impacting their relationships, an individual can lose a great deal of relational resources compared to more emotionally healthy individuals — for example, fewer instances of affection, social support, not being as satisfied or close in their relationships.”

Though men are more likely to suffer from this personality trait, many researchers have been taking a closer look as to how our culture portrays gender. Dr. Ron Levant, a professor at Harvard University, proposes the idea of “normative male alexithymia” as an answer. Levant suggests that many men are conditioned to repress their emotions, and, like many man before them, are just following in the traditional male role, leaving many men emotionally bankrupt and misunderstood.

Levant also theorized that many boys and men have been discouraged to talk about their emotions, causing them to be emotionally restricted. Hesse acknowledges that there is weight in the masculinity notion, but also believes that many studies can be contradictory. “Men in general test higher on alexithymia, perhaps due to socialization tendencies, whereby boys are told that showing emotions are a sign of weakness,” he says. “However, some studies have found a greater percentage of high alexithymic scores among women than men.”

Although alexithymia is not a well-publicized personality trait — and is often confused with other disorders — researchers are now seeing an overlap between people who have high alexithymia and Asperger’s syndrome.