The 5 Categories of Questions in an IQ Test

1. Matrices and Pattern Reasoning

This is the most iconic category in modern IQ tests. You are shown a grid of shapes with one missing piece, and you must identify the pattern to complete the sequence. These questions measure fluid intelligence — the ability to reason through an entirely new problem without prior knowledge.

Raven's Progressive Matrices, developed by psychologist John C. Raven in 1936, are the best-known example. Their advantage: they are considered one of the most culturally neutral measures available, since they require no language or accumulated knowledge.

2. Verbal Analogies and Vocabulary

Verbal analogies follow the structure: "A is to B as C is to?" They evaluate both lexical richness and the ability to identify logical relationships between concepts. This is a measure of crystallized intelligence — the knowledge you have accumulated over time.

Unlike matrices, verbal questions are more influenced by cultural and linguistic background. A native speaker has an advantage over someone who speaks the language as a second language, which is one of the recognized limitations of this type of question.

3. Number Sequences

You are presented with a series of numbers and must find the next one. The rules can be arithmetic (constant addition), geometric (multiplication), or more complex (alternating between two rules). These questions measure both logical reasoning and the ability to detect abstract structures.

Number sequences occupy an intermediate position between verbal and spatial: they require no vocabulary, but draw on a basic familiarity with arithmetic operations. They are often included in professional test batteries because of their strong prediction of performance on analytical tasks.

4. Working Memory

Working memory is the ability to hold and manipulate information in real time. In an IQ test, this typically involves repeating a sequence of digits — sometimes in reverse order — or memorizing a list while performing another task.

This is one of the components most correlated with general IQ (factor g). Research by Timothy Salthouse at the University of Virginia showed that working memory capacity declines progressively from the mid-twenties, making it a sensitive indicator of cognitive aging.

5. Spatial Reasoning

These questions ask you to mentally rotate 3D shapes, identify which piece completes a figure, or visualize how a folded object looks when unfolded. They assess the ability to manipulate visual representations in mental space.

Spatial reasoning predicts performance in fields such as engineering, architecture, and surgery. Studies from Johns Hopkins University showed that students who scored high on spatial reasoning at age 13 were overrepresented among patent holders and STEM graduates twenty years later.

Summary of the 5 Categories