Type A Personality refers to the long-standing traits and patterns that influence how a person interacts with others and responds to the world around them.
The idea of a “type A personality” dates back to 1959, when two cardiologists suggested that people who are hard-driving, impatient, and competitive were at higher risk for heart disease. Although later research did not confirm a direct link between personality type and heart disease, the concept of type A personality has remained popular and is still commonly used to describe certain behavioral tendencies.
The American Psychological Association defines personality as a combination of enduring traits, behaviors, interests, values, emotional patterns, and more—factors that shape how we adjust to life.
Traits of a type A personality
Type A is not an official psychological diagnosis, but it’s widely recognized for its consistent traits. People with type A tendencies are often described as:
- Goal-oriented
- Competitive
- Ambitious
- Impatient
They may also be organized, independent, and efficient—traits that can contribute to success. However, if negative tendencies dominate, such as being overly controlling, aggressive, or quick to anger, relationships and well-being can suffer.
Type A individuals are often highly driven to achieve their goals. While this can be a strength, it may also lead to chronic stress, both for themselves and for those around them.
Type A vs. type B
The same cardiologists who coined the term “type A” also introduced “type B” as a contrasting personality type. While the heart disease connection didn’t hold up to scientific scrutiny, the personality descriptions still resonate with many people.
People with type B traits tend to be:
- Easygoing
- Patient
- More relaxed and flexible
Type B individuals may be seen as more approachable and less reactive, but if taken to the extreme, these traits can also result in a lack of motivation or difficulty meeting goals.
In reality, most people don’t fit perfectly into either category. It’s common to identify with traits from both groups. Modern personality science now considers the A/B model to be an oversimplification of human behavior.
What about types C and D?
Over the years, researchers have proposed other types as well. Type C was described as negative and prone to cancer, while type D was labeled as distressed and more likely to experience depression. However, these ideas have not been supported by reliable scientific evidence.
How do personality types develop?
People have been trying to understand personality for centuries. In ancient times, it was believed that four bodily fluids—or “humors”—determined personality: black bile (sadness), yellow bile (anger), phlegm (calmness), and blood (cheerfulness). These ideas may seem outdated, but some of the language has persisted. For example, a “phlegmatic” person is still described as calm and unemotional, while someone who is “sanguine” is cheerful and optimistic.
Today, we know that personality develops through a combination of nature and nurture. Genetics can influence traits like shyness or extroversion, which may appear early in life. Environmental factors—such as upbringing, social influences, and role models—also shape personality. Even brain structure and chemistry may play a role in how certain traits are expressed.
Is it helpful to know your personality type?
As the Greek philosopher Aristotle once said, “Knowing yourself is the beginning of all wisdom.” Many people turn to online personality tests to gain insight into their behavior. Popular tests include the Myers-Briggs Type Indicator (inspired by Carl Jung), the Enneagram, and the Big Five Inventory.
While these tools can be fun and offer general insights, they don’t provide clinical diagnoses or offer treatment guidance. If you’re looking to make meaningful changes or better understand certain behavioral patterns, working with a mental health professional may be more helpful than taking a quiz.
When does personality become a disorder?
Personality disorders are real mental health conditions diagnosed by trained providers. Like personality traits, they involve enduring patterns of behavior and emotion—but in the case of a disorder, these patterns are rigid, deviate from cultural norms, and cause significant distress or functional problems.
Diagnoses are based on criteria outlined in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). Examples include narcissistic, paranoid, histrionic, and obsessive-compulsive personality disorders.
What if you’re struggling with personality traits?
If certain behaviors or feelings are interfering with your daily life or relationships, it may be time to talk to a mental health professional. A licensed therapist or psychologist can help you explore these challenges and provide support. If you’re not sure where to begin, your primary care provider can be a good first step—they can help you connect with the right resources for mental health care.
