Many of us are guilty of taking silly personality tests like, "What fast food chain are you?" or "What piece of furniture describes you best?" We know not to take them seriously, but there are others, like the Myers-Briggs Type Indicator (MBTI), that we trust, because a lot of psychologists once did too. However, these four-letter personality types (i.e., ISTJ or ENFP), don't mean much — they fail to include what psychologists define as personality, including thoughts, emotional responses, and behaviors.

In SciShow Psych's video, "Do Personality Tests Mean Anything?" host Brit Garner explains the key to identifying someone's personality is by looking at the individual traits people have that seem to be stable across time and apply in different contexts. The MBTI test measures people on whether they're extroverted or introverted; relies on their senses or intuition; whether they lean towards thinking or feeling; and whether they’re more likely to be judging or perceiving. Psychologist Carl Jung developed these ideas by working with patients. Katharine Cook Briggs and her daughter Isabel Briggs Myers, then sought to measure personality via the previously stated traits.

Read More: Myers-Briggs Personality Types Put To The Test

The MBTI test consists of 16 possible personality types, and even lists the career you're suited for based on your type. However, this test lacks what psychologists strive for reliability and validity. Ideally, psychologists want to have retest reliability; this means giving people the same test over time, where they'll get a similar score. Another reliability measure, known as internal consistency reliability, emphasizes measuring one component of personality at a time.

The MBTI test failed to be both reliable and valid. A study found after a five-week gap between tests, half of the people got a new type the second time. But, reliability does improve if psychologists use a numeric score instead of a category. For example, saying someone is "56 percent extroverted" conveys more reliability and validity since most people aren't extreme extroverts or introverts; they fall somewhere along the middle.

Moreover, numeric score works better, because there's a spectrum when it comes to personality traits. These traits tend to change in different situations. A better way to look at personality is through the "Big Five" personality traits, known as openness, conscientiousness, extraversion, agreeableness, and neuroticism. It doesn't assign us a personality type, but it can tell us about the individual aspects of our personality.

Personality tests may be popular, but if you're taking the MBTI test or similar, it will fall short identifying the real you.

See Also:

The 16 Personality Types And Dating For The Perfect Match

Can Your Personality Type Change?