What are the Mullen Scales of Early Learning?

The Mullen Scales of Early Learning is an individually administered developmental assessment for children from birth through 68 months of age. It measures ability in five areas (gross motor, visual reception, fine motor, receptive language, and expressive language) and combines the four cognitive scales into an overall score called the Early Learning Composite. Author Eileen M. Mullen published the combined edition in 1995 through American Guidance Service, and the test is now sold by Pearson. Clinicians use it to evaluate early intellectual development and school readiness, to document developmental delays, and, in research settings, as one of the standard cognitive measures for young children with autism. This article explains what each scale covers, how administration and scoring work, what the scores are used for, and what early-childhood scores can and cannot tell you about later intelligence.

According to Pearson, the current publisher, the test assesses language, motor, and perceptual abilities through five separate scales. Each scale is administered directly to the child by an examiner rather than through parent report.

• Gross Motor: large-muscle skills such as head control, sitting, standing, and walking. This scale covers birth through 33 months only, since large-motor milestones lose their diagnostic value for cognitive development after toddlerhood.

• Visual Reception: nonverbal visual processing, such as tracking objects, matching pictures, and discriminating shapes and details. This scale carries much of the test's nonverbal reasoning content.

• Fine Motor: small-muscle control and hand-eye coordination, from grasping objects in infancy to stacking, stringing, drawing, and copying tasks in the preschool years.

• Receptive Language: understanding of spoken language, from turning toward sounds in infancy to following directions and pointing to named pictures later on.

• Expressive Language: the child's own spoken output, from babbling and first words to naming, answering questions, and forming sentences.

The four scales other than Gross Motor are considered the "cognitive scales," and they are the ones that feed the overall composite score described below.

The Mullen Scales span birth to 68 months, which is roughly five years and eight months. The Gross Motor scale stops at 33 months, while the four cognitive scales run the full age range. After 68 months, examiners move to preschool and school-age intelligence tests such as the ones covered in our article on the WPPSI test (https://www.riotiq.com/articles/specific-iq-tests-and-formats/what-is-the-wppsi-test).

Administration is one-on-one and interactive. The examiner presents brief tasks in a standardized sequence and records the child's responses. To the child, a good session looks much like structured play, although the examiner is following set procedures and scoring rules throughout. Pearson reports typical administration times of about 15 minutes at age 1, 25 to 35 minutes at age 3, and 40 to 60 minutes at age 5. The publisher restricts the test to qualified professionals, and it is typically given by psychologists, early-intervention specialists, and trained research staff.

Testing very young children takes skill. In a 2006 study in Child Neuropsychology, Natacha Akshoomoff coded children's behavior during Mullen administrations and found that scores were meaningfully correlated with how engaged the child was during the session, and negatively correlated with off-task behavior. A skilled examiner who keeps a toddler engaged is part of what makes the score valid.

Each of the five scales produces a "T score," a standardized score with a mean of 50 and a standard deviation of 10, along with percentile ranks and age equivalents. A T score of 50 means performance exactly at the average for the child's age, and a T score of 40 is one standard deviation below average.

The four cognitive scales (Visual Reception, Fine Motor, Receptive Language, and Expressive Language) combine into the Early Learning Composite. The composite is reported as a standard score with a mean of 100 and a standard deviation of 15, the same metric used by IQ tests. That makes the Early Learning Composite loosely comparable to an IQ score for a young child, although the publisher frames it as a measure of early intellectual development and readiness for school rather than a formal IQ.

One practical advantage over some infant tests is that the Mullen separates verbal and nonverbal performance. Akshoomoff noted that the older Bayley Scales of Infant Development yielded a single overall estimate, while the Mullen lets a clinician compare language scales against visual and motor scales directly. That matters because many children referred for evaluation show uneven profiles, with language lagging far behind nonverbal ability or the reverse.

In clinical practice, the Mullen Scales help answer two common questions: is this child developing on schedule, and if there is a delay, in which domains? Results are used in developmental delay evaluations, early-intervention eligibility decisions, and school-readiness assessments.

The test also has an unusually large footprint in autism research. Somer Bishop, Whitney Guthrie, and colleagues, writing in the American Journal on Intellectual and Developmental Disabilities in 2011, described the Mullen as frequently used in research and clinical evaluations of children with autism spectrum disorders and noted that it had been selected as one of the preferred cognitive measures in multisite collaborative projects. In their study of children with autism, Mullen scores converged well with the Differential Ability Scales: nonverbal scores correlated .74 and verbal scores correlated .83 across the two instruments, and roughly seven in ten children landed in the same ability range on both tests.

The Mullen has known limits in these populations. Its lowest possible T score is 20, which sits three standard deviations below the mean. In Akshoomoff's sample of preschoolers with autism spectrum disorders, 73 percent received at least one T score at that floor, which means the standard scores could not distinguish among the lowest performers. Researchers often fall back on age-equivalent scores in those cases, a workaround that she described as useful but potentially misleading if over-interpreted.

Scores from infancy and toddlerhood should be read as a snapshot of current development, and only cautiously as a forecast. Evidence on comparable infant measures shows why. A 2023 study in PLOS Global Public Health by Muneera Rasheed and colleagues followed about 1,200 children in rural Pakistan and found that Bayley-III scores at age 2 explained only 15 percent of the variation in Full Scale IQ on the WPPSI-III at age 4. The authors concluded that scores at age 2 should be used with caution when predicting later abilities.

Stability improves with age, and prediction is stronger at the low end of the range, where substantial delays tend to persist. Even so, individual change is common. Molly Prigge and colleagues, following people with autism from age 3 (tested with the Mullen or the Differential Ability Scales) into adulthood in the Journal of Autism and Developmental Disorders, found that more than half of participants with repeated testing had at least one IQ score fall outside the 95 percent confidence interval of their other scores, and cautioned that an IQ estimate obtained at an early age may differ significantly from IQ measured later. For a broader look at how scores move across the lifespan, see our articles on whether IQ changes with age (https://www.riotiq.com/articles/iq-scores-and-interpretation/does-iq-change-with-age) and on cognitive development (https://www.riotiq.com/articles/advanced-topics-and-research/cognitive-development).

The honest summary: an Early Learning Composite far below average is a strong signal that a child needs support now, and low scores become more predictive the more severe the delay. A composite in the average or high range for a toddler says much less about where that child will score at age 10 or 20.

The Mullen Scales illustrate what serious measurement looks like at the start of life: individual administration, national norms, separate domain scores, and honest limits on interpretation. The same standards apply when adults want a trustworthy read on their own cognitive abilities. The RIOT IQ test (the Reasoning and Intelligence Online Test), developed by RIOT IQ with psychometrician Dr. Russell T. Warne, applies those standards to adult online testing: 15 subtests across six cognitive indices (verbal reasoning, fluid reasoning, spatial ability, working memory, processing speed, and reaction time), scored on the familiar mean-100, standard-deviation-15 scale, in about 52 minutes. It is designed for adults 18 and older, and like any online measure it does not replace an individually administered diagnostic evaluation. If you want a rigorous estimate of your own abilities as an adult, you can take the RIOT IQ test at riotiq.com (https://www.riotiq.com/).

Birth through 68 months. The four cognitive scales cover the whole range, while the Gross Motor scale is used only from birth to 33 months.

Not formally. It is a developmental assessment, but its Early Learning Composite uses the same mean-100, standard-deviation-15 metric as IQ tests and is often treated as a cognitive ability estimate in research.

Qualified professionals such as psychologists and early-intervention specialists. Pearson lists it at qualification level B, which requires relevant graduate training or certification.

About 15 minutes for a 1-year-old, 25 to 35 minutes for a 3-year-old, and 40 to 60 minutes for a 5-year-old, according to the publisher.

It covers the youngest ages at which autism is diagnosed, gives separate verbal and nonverbal scores, and has been adopted as a preferred cognitive measure in large multisite studies, so results are comparable across projects.

No single early score fixes a child's future. Substantial delays do tend to persist and justify early intervention, but longitudinal research finds that individual scores often shift meaningfully between early childhood and later ages.

1. Pearson. (n.d.). Mullen Scales of Early Learning [Product page]. Pearson Assessments. pearsonassessments.com

2. Akshoomoff, N. (2006). Use of the Mullen Scales of Early Learning for the assessment of young children with autism spectrum disorders. Child Neuropsychology, 12(4-5), 269-277. pubmed.ncbi.nlm.nih.gov

3. Bishop, S. L., Guthrie, W., Coffing, M., %26 Lord, C. (2011). Convergent validity of the Mullen Scales of Early Learning and the Differential Ability Scales in children with autism spectrum disorders. American Journal on Intellectual and Developmental Disabilities, 116(5), 331-343. pmc.ncbi.nlm.nih.gov

4. Rasheed, M. A., Kvestad, I., Shaheen, F., Memon, U., %26 Strand, T. A. (2023). The predictive validity of Bayley Scales of Infant and Toddler Development-III at 2 years for later general abilities: Findings from a rural, disadvantaged cohort in Pakistan. PLOS Global Public Health, 3(1), e0001485. pmc.ncbi.nlm.nih.gov

5. Prigge, M. B. D., Bigler, E. D., Lange, N., et al. (2022). Longitudinal stability of intellectual functioning in autism spectrum disorder: From age 3 through mid-adulthood. Journal of Autism and Developmental Disorders, 52(10), 4490-4504. pmc.ncbi.nlm.nih.gov

6. Critical Path Institute. (n.d.). Mullen Scales of Early Learning. Rare Disease Clinical Outcome Assessment Resource. rdcoas.c-path.org

Hero photo: A toddler's hands playing with a colorful ring-stacking toy. Photo by Shypoetess via Wikimedia Commons, licensed under CC BY-SA 4.0 (cropped).