Glossary
Processing speed
Definition
Processing speed is how quickly a person can take in simple information and respond to it accurately, such as scanning a row of symbols for a match. It is measured on easy tasks, where nearly everyone would be correct given enough time, so speed is what separates people.
Want your own number? The test is 25 visual puzzles, about 12 minutes, no sign-up.
Why it matters for IQ scores
Speed matters on any timed test, and some clinical batteries measure it directly. It is also the ability that changes most clearly with age: processing speed and some reasoning measures peak in the late teens and twenties, while vocabulary and knowledge keep rising into the sixties (Hartshorne & Germine, 2015) (Salthouse, 2009).
Why age does not lower your IQ
Because IQ is scored against age norms, a typical slowing with age does not lower a person's score by itself. A 60-year-old is compared with other 60-year-olds, who have slowed in similar ways. The deviation IQ is relative to same-age peers, so the comparison stays fair.
On IQ Octopus
The test has a soft time budget of about 12 minutes for most people and a hard cap of 20. It records how long you take on each puzzle and shows a descriptive speed label, but scoring is based on your answers. Rushing usually costs more accuracy than it saves time.
Common confusions
Fast is not the same as smart, and slow and careful is a fine way to take a reasoning test. Speed is one ability among several. Related terms: working memory and crystallized intelligence. For the research in depth, read IQ and age.
Speed and age
Timothy Salthouse's processing-speed theory proposes that adult aging slows many mental operations and that this slowing impairs other cognitive functions (Salthouse, 1996). The full explanation: what processing speed is.
Try one · Quantitative Reasoning
Which number comes next?
11, 18, 27, 38, 51, ?
Tap the option you think is right, or show the answer.
Show the answer
The next number is 66 (option 3).
How to solve it
- The gaps (7, 9, 11, 13) grow by 2 each time, which is the pattern of square numbers.
- Each number is a square number plus 2: 3 × 3 + 2, 4 × 4 + 2, 5 × 5 + 2, 6 × 6 + 2, 7 × 7 + 2.
- So the next number is 8 × 8 + 2 = 66.
That was 1 puzzle. The full test has 25.
Sources
- Hartshorne, J. K., & Germine, L. T. (2015). Psychological Science, 26(4), 433-443. doi.org/10.1177/0956797614567339
- Salthouse, T. A. (2009). Neurobiology of Aging, 30(4), 507-514.
- Salthouse, T. A. (1996). The processing-speed theory of adult age differences in cognition. Psychological Review, 103(3), 403-428. doi.org/10.1037/0033-295X.103.3.403