Is 115 a Good IQ Score? Exactly One Standard Deviation

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What one standard deviation actually means

IQ scores are standardised so that the population mean is 100 and the standard deviation is 15. A score of 115 is therefore precisely 1.0 standard deviations above average, which makes it the reference point the whole rest of the scale is described against. When you read that 130 is “two standard deviations” or 145 is “three,” the unit being counted is the distance between 100 and your score.

The practical translation of one standard deviation is the 84th percentile. Put another way: of every six people, roughly one scores at or above you and five score below. That is a genuinely useful rule of thumb, and it is worth holding onto because it is the number most people get wrong in both directions. 115 is not borderline average, and it is not rare.

On the Wechsler classification system, 115 sits comfortably inside the second band from the middle:

• IQ 90-109: Average
• IQ 110-119: High Average, and 115 is the midpoint
• IQ 120-129: Superior, relabelled Very High in current Wechsler editions
• IQ 130 and above: Very Superior, conventionally called gifted

The exact percentile for an IQ of 115

Using the standard normal distribution, an IQ of 115 maps to the 84.13th percentile. Here is how it compares with its neighbours:

In concrete terms: in a school class of 30, about five pupils would be expected to reach 115. In a 100-person office, roughly sixteen. You are above average in a way that shows up in daily life, while still being common enough that you will regularly work alongside people who match or exceed you.

115 is the average IQ of a PhD holder

This is the fact about 115 that most people find hardest to believe, and it is worth sitting with. In Kaufman and colleagues' (2016) analysis of WAIS-IV normative data, the mean IQ of adults holding a doctorate is around 115. The full ladder runs:

• High school graduates: mean IQ around 99
• Bachelor's degree holders: mean IQ around 110
• Master's degree holders: mean IQ around 112
• Professional degrees (MD, JD): mean IQ around 114
• Doctoral degrees (PhD): mean IQ around 115

Two things follow, and they point in opposite directions, which is why this is interesting rather than merely flattering.

The first is about you. If you have wondered whether you have the cognitive equipment for postgraduate study, the data says you are sitting exactly at the average of people who completed it. Not near it. At it. Whatever has determined your educational path, raw capability was not the ceiling.

The second is about doctorates, and it is the more important lesson. The popular image of “PhD-level intelligence” imagines something around 140. The actual figure is 115, and the gap between the image and the number tells you what doctoral study really selects for: tolerance for years of low pay, willingness to work on one narrow question long past the point of novelty, access to funding and supervision, and the sheer stubbornness to finish. Cognitive ability is the entry ticket, not the differentiator.

The usual caveat applies in both directions. The correlation between IQ and educational attainment mostly reflects selection, meaning more able people tend to pursue more education, rather than causation. Ritchie and Tucker-Drob (2018) put the causal effect of schooling on measured IQ at roughly 1 to 5 points per additional year. A 115 with no degree is exactly as real as a 115 with a doctorate.

What one standard deviation actually buys you

The occupational research gives unusually concrete answers here, and 115 sits in a well-documented part of the range. Gottfredson's (1997) synthesis mapped cognitive ability onto job complexity and the kind of learning each level supports. The relevant landmarks:

• Above IQ 110, people can generally learn a great deal independently and from the typical university teaching format, meaning lectures and set reading rather than close supervision.
• Around IQ 112 is the level at which people become competitive for roles such as accountant and teacher.
• Above IQ 116, people can reliably gather and synthesise information and infer conclusions from unstructured on-the-job situations, which is the core skill of most professional work.
• Around IQ 120 is where people become competitive for the most cognitively demanding roles, such as research analyst.
• Virtually every occupation accommodates people down to IQ 110, while employment options narrow sharply below IQ 80.

Read against that ladder, 115 is above the point where the entire labour market is open to you and one point below the threshold associated with independently synthesising messy information at work. Which is to say you are inside the professional band with a little room, rather than at either edge of it.

Worth stating plainly: those figures describe group averages and typical competitiveness, not hard gates. People below a listed threshold succeed in those roles constantly, and people above them fail. The numbers describe where the odds sit, not who is allowed in.

The score that comes with no label

Here is something nobody writes about 115, and it is probably why you are reading this page rather than simply knowing the answer.

Almost every other notable score on the scale comes attached to something. 130 gets you into Mensa and the gifted range. 120 flips the classification to Superior. 100 is the definitional average and needs no explanation. 115 gets none of that. There is no club, no programme, no tier name, and no school ever pulled a child aside because they scored 115. The band label, High Average, is about as motivating as it sounds.

That absence is informative rather than disappointing. The labels are administrative conventions, drawn to serve institutions that needed cut-offs. What 115 actually describes is a person who will find most intellectual work tractable, who can learn new fields from books without much hand-holding, and who is better positioned than five out of six people for anything cognitively demanding. That is a substantial thing to be true of someone. It simply does not come with a certificate.

How much to trust a single score of 115

The WAIS-IV has a test-retest reliability of about 0.96 for Full Scale IQ, which is excellent but not perfect, and the standard error of measurement is typically plus or minus 3 to 5 points. If you scored 115, your true underlying ability most likely sits between 110 and 120.

The good news specific to this part of the scale is that measurement is at its most reliable here. Standardisation samples contain thousands of people around one standard deviation from the mean, so the norms are densely anchored, and tests agree with each other closely. That is the opposite of the situation above 130, where a handful of people in the sample anchor each band and different scales pull apart.

The practical read: a 115 from a decent test is one of the more trustworthy numbers you can be handed. It should still be treated as a range rather than a point, but the range is narrow and honestly estimated.

Can you join Mensa with an IQ of 115?

No. Mensa requires a score at or above the 98th percentile, which is IQ 130 on the Wechsler scale and 132 on older Stanford-Binet scales using a standard deviation of 16. An IQ of 115 is at the 84th percentile, so 15 points short.

Fifteen points is well outside anything measurement error will bridge, so a retest is not a realistic route unless you have specific reason to think one sitting badly understated you. It is also worth keeping the goal in proportion: Mensa is a social club with a cognitive entry ticket, and membership correlates weakly with income, career progression, relationships or life satisfaction. At 115 you are already above the accommodation threshold for essentially the entire labour market, which is the thing that actually affects your life.

What to keep in mind about an IQ of 115

A few things worth knowing so you can read your score accurately, not to talk it down, but because understanding them makes the number more meaningful.

• It is the most reliably measured part of the scale. Unlike scores above 130, a 115 is anchored on thousands of people in any standardisation sample. If your test was reasonable, the number is trustworthy.
• You match the average doctorate holder. That is worth knowing because it corrects a widespread misconception about what high-level academic work requires. If postgraduate study appeals to you, ability is not the obstacle.
• The remaining variance is where your life actually happens. Cognitive ability correlates with job performance at around 0.5 for complex roles, with educational attainment at around 0.5 and with income at roughly 0.3 to 0.4. Those are meaningful, and they leave most of the outcome unexplained. Conscientiousness, health, timing, network and what you choose to get good at account for more of the difference between people at your level than any remaining IQ points would.
• It captures one kind of intelligence. IQ measures the general factor behind reasoning and problem-solving, which is important and well studied. Creativity, judgement, emotional intelligence and deep domain expertise all shape how people actually do, and a 115 is silent on all of them. They could easily be higher.

The bottom line on IQ 115

An IQ of 115 is a good score. You are exactly one standard deviation above the mean, at the 84th percentile, roughly 1 in 6, in the High Average range, and level with the average person holding a doctorate. Virtually every occupation is open to you on cognitive grounds, and you sit just below the threshold associated with independently synthesising complex information at work.

What 115 lacks is a label, and that is the whole reason this score confuses people. There is no club to join and no tier to belong to, so the number arrives without a story attached. The story it deserves is that you are better placed than five out of six people for anything intellectually demanding, measured more reliably than any score at the extremes, and limited by what you choose to do rather than by what you are able to do.

And if your 115 came from a short quiz, it is worth confirming against something longer. This part of the scale is measured well by good tests and sloppily by bad ones.

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