IQ explained · 6 min read
What counts as a good IQ score, and what it does not tell you
Where 110, 120 and 130 sit on the curve, what IQ scores predict and how weakly, when a score matters and when it is a distraction. No number is a verdict on a person.
In short
"Good" is a comparison, so it needs a reference group. On the standard scale 110 is about the 75th percentile, 120 about the 91st and 130 about the 98th. Scores in that region are associated with somewhat better average outcomes in schooling and some jobs, but the associations are modest and leave most of the variation unexplained. A score matters when a decision depends on a professionally administered test; outside that, it is mostly a number people compare for its own sake.
Good compared with whom
A score of 120 is higher than about nine in ten people in the norm sample, which is why it is often described as a good score. A score of 110 is higher than about three in four. A score of 130 is higher than about 49 in 50, which is the region high-IQ societies use as an entry line. None of these statements says anything about the person beyond a rank in a reference group on the sampled abilities, on that day.
What IQ scores predict, and how much
Decades of research find that scores on general cognitive ability tests correlate positively with school grades, years of education and performance in training and in complex jobs. The correlations are real and they are moderate: in most studies they leave the majority of the differences between people unexplained. Motivation, health, opportunity, personality and practice carry the rest. A high score therefore shifts the odds; it does not decide the outcome, and a lower score does not close a door.
When a score matters
An IQ score matters when a decision formally depends on it: eligibility for an educational programme, a clinical assessment that combines the score with history and interviews, or a research study. In those settings the test is administered by a trained professional under standard conditions, and the report includes confidence intervals and subscale patterns that mean more than the headline number.
Outside those settings, a number from an online quiz has no decision attached to it. That is not a reason to avoid reasoning tests; it is a reason to read them for what they show, which is the kind of problem you solved and the kind you did not.
How to read a MyTestAtlas result instead
Our reasoning tests report raw accuracy by rule family and by difficulty tier, then list every item with your answer and the correct one. A result such as "27 of 36; all six figure matrices solved; two of eight number series missed at the hard tier" is more specific than any single score, and it tells you what to practise next.
Sources
- The American Psychological Association's topic page on intelligence collects its public material on how intelligence is defined and measured.
- The Standards for Educational and Psychological Testing (AERA, APA and NCME, 2014) set the professional requirements for test norms, reliability, validity and fairness.
Text on this page is original to MyTestAtlas. It explains published standards and definitions; it is not psychological, medical or admissions advice.