Type A and Type B are two broad personality categories originally developed in the 1950s by cardiologists Meyer Friedman and Ray Rosenman. Type A describes people who are competitive, time-driven, and easily frustrated. Type B describes people who are more relaxed, flexible, and patient. The framework was initially created to study heart disease risk, not personality for its own sake, which explains both its appeal and its limitations.
Core Type A Traits
The Type A pattern revolves around urgency and intensity. People who fit this profile tend to be highly competitive, impatient with delays, and driven by deadlines. They often set ambitious goals and feel restless when they’re not being productive. Conversations may feel rushed, and they can become visibly irritated when things move slowly.
One of the more interesting findings from early research is that Type A individuals literally perceive time differently. In studies measuring time awareness, people with strong Type A traits consistently underestimated how much time had passed during a fixed interval. They experience minutes as longer than they actually are, which helps explain the constant sense that time is running out.
Hostility is another hallmark. Friedman and Rosenman specifically noted that Type A people tend toward aggressive, easily triggered frustration, not just ambition. This distinction matters because later research found that the hostility component, not the drive or competitiveness, was the piece most closely linked to health outcomes.
Core Type B Traits
Type B is essentially the opposite profile: easygoing, even-tempered, and comfortable without a packed schedule. People who fit this description tend to be patient, adaptable to change, and less focused on squeezing maximum efficiency out of every moment. They need time and space to work at their own pace and don’t respond well to being rushed.
Type B individuals often thrive in collaborative and creative settings. They tend to enjoy brainstorming, sharing ideas freely, and caring as much about the process as the end result. They’re typically happy to share credit for success rather than competing for individual recognition. The tradeoff is a greater tendency to procrastinate, since the internal pressure to finish quickly simply isn’t there.
From a health perspective, the Type B profile carries some advantages. Lower baseline stress and better stress management skills are associated with reduced risk of heart disease and high blood pressure. There’s also some evidence that chronic low-level stress suppresses immune function over time, giving more relaxed individuals a slight edge in overall health resilience.
The Heart Disease Connection
The entire Type A/B framework started as a cardiovascular theory. Friedman and Rosenman believed that the hard-charging, hostile Type A pattern was a risk factor for coronary heart disease. Early studies seemed to support this, and the idea became enormously popular in both medicine and popular culture during the 1970s and 1980s.
Later research, however, couldn’t replicate those early findings. A large meta-analysis covering studies from 1966 through 1998 found no association between the overall Type A behavior pattern and heart disease. The broad category of “Type A” was too blunt an instrument. Researchers then narrowed their focus to anger and hostility specifically, which did show a more consistent link to coronary problems. So it’s not ambition or time urgency that appears to strain the heart. It’s chronic anger and hostile reactions to everyday frustrations.
Why Most People Don’t Fit Neatly
If you’ve ever taken an online quiz and felt like you were a mix of both types, that’s not a flaw in your personality. It’s a flaw in the framework. Personality psychologists have largely moved away from the Type A/B system because it forces a spectrum into two boxes. As researchers at the University of Queensland put it, describing personality with just two types is like describing how someone looks using only “tall” and “short.” Even if the categories contain some truth, they’re too crude to be useful.
Most people fall somewhere between the two poles. You might be fiercely competitive at work but completely laid-back on weekends. You might be patient with people but hostile toward slow technology. The binary system has no way to capture that kind of nuance.
How Personality Science Has Evolved
The most widely accepted model in modern psychology is the Big Five, which measures personality across five continuous spectrums rather than sorting people into categories. These five traits are openness to experience, conscientiousness, extraversion, agreeableness, and emotional stability (sometimes called its inverse, neuroticism). Each one is a sliding scale, not an either/or label.
Under this model, someone who would have been called “Type A” might score high in conscientiousness and low in agreeableness, while a “Type B” person might score high in openness and agreeableness but lower in conscientiousness. The Big Five captures the same real differences in behavior that Friedman and Rosenman noticed, but with far more precision and much stronger scientific support.
That said, the Type A and Type B labels remain deeply embedded in everyday conversation. Most people use them as shorthand, and in that informal sense they still communicate something real. You probably do know people who can’t sit still and people who never seem stressed. The labels just aren’t reliable enough to predict health outcomes, job performance, or relationship compatibility the way pop psychology often implies.
How Type A/B Was Originally Measured
If you’re curious whether the classification was ever more than a casual label: yes, formal assessment tools do exist. The most well-known is the Jenkins Activity Survey, a self-report questionnaire developed to measure the Type A pattern. The Framingham Type A Scale is another, created as part of the famous Framingham Heart Study. Both ask questions about work habits, time pressure, and reactions to frustration. A more detailed tool called the Survey of Work Styles breaks the pattern into six specific subscales rather than producing a single A-or-B result.
These tools were designed for research, not personal discovery. The online quizzes you’ll find today are simplified versions with no clinical validation. They can be fun and occasionally insightful, but they measure self-perception more than actual behavior patterns.