The Stanford-Binet Intelligence Scale produces a rich set of scores — not just a single IQ number, but a detailed cognitive profile that reveals how you think. This guide explains what each score means and how to interpret the results in context.

How the Stanford-Binet Intelligence Scale Works

The Stanford-Binet Fifth Edition (SB5) measures general cognitive ability across five factors: Fluid Reasoning, Knowledge, Quantitative Reasoning, Visual-Spatial Processing, and Working Memory. Each factor is tested through both verbal and nonverbal tasks, producing 10 subtests in total.

The test uses adaptive routing — two initial subtests determine your starting difficulty for the remaining eight. This means you always encounter items near your ability level, making the test both efficient and accurate.

The Score Types

The SB5 produces several layers of scores, each offering a different lens on cognitive ability:

  • Subtest Scaled Scores — each of the 10 subtests produces a score with a mean of 10 and SD of 3. Scores of 7–13 fall within the normal range.
  • Factor Index Scores — each of the five factors combines its verbal and nonverbal subtests into a score with mean 100 and SD 15.
  • Full Scale IQ (FSIQ) — all 10 subtests combined. The most general measure of cognitive ability.
  • Verbal IQ (VIQ) — all five verbal subtests. Predicts academic success in language-heavy subjects.
  • Nonverbal IQ (NVIQ) — all five nonverbal subtests. Valuable for individuals with language barriers.
  • Abbreviated Battery IQ (ABIQ) — the two routing subtests only, for a quick screening estimate.

Score Classification

Stanford-Binet scores follow a standard classification system. Remember that “average” is where most people score — it is not a limitation:

145–160Very Gifted / Highly Advanced99.9th %ile~1 in 1,000
130–144Gifted / Very Advanced98th–99.8th~2 in 100
120–129Superior91st–97th~7 in 100
110–119High Average75th–90th~16 in 100
90–109Average25th–74th~50 in 100
80–89Low Average10th–24th~16 in 100
70–79Borderline Impaired or Delayed2nd–9th~7 in 100
55–69Mildly Impaired or Delayed0.1st–2nd~2 in 100
40–54Moderately Impaired or Delayed<0.1st<1 in 1,000

What Percentile Means

A percentile rank tells you what percentage of same-age peers scored at or below a given score. If a child scores at the 90th percentile, they performed as well as or better than 90% of peers in the standardization sample. This does not mean they got 90% of the questions right — percentile and percentage correct are entirely different measures.

Interpreting Factor Profiles

The overall FSIQ is the most commonly reported number, but the factor profile is often more informative. Two people with identical Full Scale IQs can have very different minds. To understand what each factor measures in detail, see our Stanford-Binet subtests guide. These common patterns reveal how profiles differ:

Flat Profile

All factors within a few points of each other. Cognitive abilities are relatively evenly developed. The FSIQ accurately represents overall functioning.

Verbal > Nonverbal

Stronger language-based abilities. May indicate strong reading and verbal reasoning, educational advantages, or some learning differences like nonverbal learning disorder.

Nonverbal > Verbal

Stronger visual and hands-on reasoning. Common in English Language Learners whose cognitive ability is underestimated by verbally loaded tests. May also indicate spatial talent.

High Fluid, Lower Knowledge

Strong reasoning ability with less accumulated learning. Often seen in younger children from enriched but non-academic environments, or strong thinkers who aren’t avid readers.

Low Working Memory

Difficulty holding information under load, with other factors normal. Commonly associated with attention difficulties (ADHD). May explain struggles with multi-step math and reading comprehension despite otherwise strong ability.

Common Misunderstandings About IQ Scores

Common Misconception

“My child scored 120 — they’re almost gifted.”

IQ scores don’t work on a linear scale like test grades. The difference between 120 and 130 is more meaningful than the difference between 100 and 110, because each standard deviation above the mean represents an increasingly smaller percentage of the population.

Common Misconception

“This score will follow them forever.”

IQ scores are reasonably stable from about age 8 onward, but they are not fixed. Scores can change due to development, education, health, and motivation. Scores at very young ages (under 5) should be interpreted with particular caution.

Common Misconception

“A higher score means my child is smarter.”

IQ scores have a margin of error called the confidence interval — typically ±3 to ±5 points. A child who scores 127 and a child who scores 131 may have effectively identical cognitive ability. The test measures with precision, but not with perfection.

Common Misconception

“The test is biased.”

The SB5’s normative sample was carefully matched to the U.S. Census for race/ethnicity, geography, socioeconomic status, and education. Equal nonverbal and verbal components were specifically designed to reduce cultural and linguistic bias. However, no test is perfectly bias-free, and results should always be interpreted in context.

Important

Intelligence is complex and multifaceted. The Stanford-Binet measures important cognitive abilities, but it doesn’t capture everything about a person’s potential, creativity, emotional intelligence, or practical skills. Your factor profile reveals your unique cognitive fingerprint — use it as a tool for understanding, not a label.