Fluid vs. Crystallized Intelligence

Balancing mental flexibility and accumulated wisdom

Fluid vs. crystallized intelligence are two types of intelligence that influence your ability to function effectively in your daily life. Fluid intelligence involves the ability to reason and think flexibly, whereas crystallized intelligence refers to the accumulation of knowledge, facts, and skills acquired throughout life.

The theory of fluid vs. crystallized intelligence was first proposed by psychologist Raymond Cattelwith his student John Horn. The theory suggests that intelligence comprises different abilities that interact and work together to produce overall individual intelligence.

Some people say that intelligence starts to decline as people age. However, research suggests that while fluid intelligence begins to decrease after adolescence, crystallized intelligence continues to increase throughout adulthood.

Fluid Intelligence vs Crystallized Intelligence
Verywell / Emily Roberts

Fluid Intelligence

Cattell defined fluid intelligence as "the ability to perceive relationships independent of previous specific practice or instruction concerning those relationships."

Fluid intelligence involves being able to think and reason abstractly and solve problems. This ability is considered independent of learning, experience, and education.

When you encounter an entirely new problem that cannot be solved with your existing knowledge, you must rely on fluid intelligence to solve it.

Fluid intelligence examples include:

Fluid intelligence tends to decline during late adulthood. Certain cognitive skills associated with fluid intelligence also tend to decline as people reach later adulthood.

Crystallized Intelligence

Crystallized intelligence involves knowledge that comes from prior learning and past experiences. In other words, it's all of the facts, figures, and other accumulated knowledge that you've acquired over the course of your life.

Crystallized intelligence is based upon facts and rooted in experiences. As we age and accumulate new knowledge and understanding, crystallized intelligence becomes stronger.

Crystallized intelligence examples include:

  • Memorizing text
  • Memorizing vocabulary
  • Recalling how to do something
  • Remembering dates and locations

So, what can you do to increase your crystallized intelligence? As you might expect, this type of intelligence tends to increase with age. The more learning and experience you have, the more you build up your crystallized intelligence.

Differences Between Fluid and Crystallized Intelligence

Fluid and crystallized intelligence are very important but serve different purposes. Think of them a bit like two sides of the same coin. While they are vital for your ability to function and interrelated in many ways, there are several ways in which each intelligence type is distinct.

Fluid Intelligence
  • Refers to current ability

  • Involves openness to learning new things

  • Decreases with age

Crystallized Intelligence
  • Refers to prior learning

  • Involves recalling specific facts

  • Increases with age

Both fluid and crystallized intelligence are factors that Cattell referred to as general intelligence. General intelligence is your broad cognitive capacity. It is often referred to as g-factor or IQ.

While fluid intelligence involves our current ability to reason and deal with complex information around us, crystallized intelligence involves learning, knowledge, and skills that are acquired over a lifetime.

Despite its name, crystallized intelligence is not a form of fluid intelligence that has become "crystallized." Instead, the two facets of general intelligence are considered separate and distinct.

Changes in Fluid vs. Crystallized Intelligence

Fluid and crystallized intelligence tends to change throughout life, with certain mental abilities peaking at different points. Young people may think more quickly, but older people have a larger bank of general knowledge.

In general, fluid intelligence tends to be sharpest in early adulthood, while crystallized intelligence continues to grow through life.

Fluid intelligence has long been believed to peak quite early in life, but some research suggests that some aspects of fluid intelligence may peak as late as age 40. Crystallized intelligence does tend to peak later in life, hitting its apex around age 60 or 70.

Some things to remember about fluid and crystallized intelligence:

  • Both types of intelligence increase throughout childhood and adolescence.
  • Crystallized intelligence continues to grow throughout adulthood.
  • Many aspects of fluid intelligence peak in adolescence and begin to decline progressively beginning around age 30 or 40.

Fluid and Crystallized Intelligence Tests

Intelligence testing has been the subject of a lot of debate and interest in psychology, yet many experts believe that standard IQ tests don't fully capture a person's fluid and crystallized intelligence levels.

Many of these tests are also thought to be affected by various biases that impact their results. However, a number of tests are often used to measure both fluid and crystallized intelligence.

Tests that measure fluid intelligence:

  • Raven's Progressive Matrices Test (RPM) is a non-verbal assessment that asks a person to examine various shapes and pick from a choice of shapes to complete a pattern.
  • Woodcock-Johnson Test of Cognitive Abilities measures cognitive skill and achievement; it's often given to children to assess them for advanced academic courses.
  • Wechsler Intelligence Scale for Children measures verbal, reasoning, and memory skills. It is primarily administered to children between the age of six and 16.

Tests that measure crystallized intelligence:

  • Vocabulary and general knowledge tests
  • Wechsler Adult Intelligence Scale (WAIS) is a measure of cognitive abilities developed for adults. It provides separate scores for different areas as opposed to an overall intelligence score.

How to Improve Fluid and Crystallized Intelligence

Past research on intelligence suggested that people really didn't have much control over their intelligence at all. Instead, it was believed that our IQ was largely determined by genetics and that training programs aimed at increasing IQ tended to have limited effectiveness.

More recently, evidence has found that it is possible to improve aspects of fluid intelligence, such as processing speed. How? It involves using brain training, also known as cognitive training, to help sharpen your skills.

The researchers discovered, however, that the training also increased unrelated cognitive skills, including the ability to reason and solve new problems independently of previously acquired knowledge.

In essence, with training, a person may engage the abstraction of thoughts and ideas as readily as applying knowledge-based reasoning.

How to Improve Fluid Intelligence

  • Challenge yourself
  • Mix up your routine
  • Think creatively
  • Socialize regularly

Crystallized intelligence, on the other hand, is something that can be improved through learning. The more accumulated knowledge you have, the more crystallized intelligence you will possess.

How to Improve Crystallized Intelligence

  • Learn a new language
  • Learn a new skill
  • Take a class
  • Read books

Seeking new knowledge helps build your crystallized intelligence over time, but challenging yourself with new experiences can improve your fluid intelligence as well.

How Fluid and Crystallized Intelligence Work Together

Which type of intelligence is more important? The reality is that both types of intelligence are equally important in everyday life.

For example, when taking a psychology exam, you might need to rely on fluid intelligence to come up with a strategy to solve a statistics problem. At the same time, you must also employ crystallized intelligence to recall the exact formulas you need to use.

Though each is a distinct type of intelligence, fluid and crystallized intelligence are intertwined. We use our fluid intelligence as we learn new things, and it is through learning new things that we acquire more crystallized intelligence.

By using fluid intelligence to reason and think about problems, information can be transferred to long-term memory and become part of crystallized intelligence.

Takeaways

Study participants usually engage in intensive and difficult brain training tasks over relatively short periods of time. This doesn't mean the same techniques can't be applied to your own life. The principles are the same.

Seek out new challenges. Gains in intelligence don't come from sticking to the same old routines. Keep exploring new things in life and keep learning new things. Tackle learning a new language. Take piano lessons. Visit a new country and learn about the people and culture.

All of these types of activities keep your brain engaged, challenged, and focused on learning new things in new ways.

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Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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Additional Reading
Kendra Cherry

By Kendra Cherry, MSEd
Kendra Cherry, MS, is a psychosocial rehabilitation specialist, psychology educator, and author of the "Everything Psychology Book."