13 votes
Accepted

What is the meaningful difference between someone with a 145 IQ compared to a 100 IQ?

As a general note, precision in measurement of intelligence declines as you move to more extreme levels. There is greater uncertainty in measurement in the 145 range than there is at the 100 range. ...
Jeromy Anglim's user avatar
12 votes
Accepted

Is Fluid Intelligence Dropoff With Age an Established Fact?

You are asking two very excellent questions. Is the decline in fluid intelligence commonly accepted as true? These days it seems generally accepted, that the trend is true. However, this hasn´t been ...
bucky's user avatar
  • 443
10 votes

Is there any evidence that fluid intelligence is malleable?

Is there any evidence of malleability of fluid intelligence? In the downward direction, definitely yes. There are many ways you can directly pull fluid intelligence downwards. Things like being ...
Eff's user avatar
  • 700
10 votes

Does practicing Ravens Progressive Matrices tests inflate your IQ score?

Yes, practice even as simple retest improves scores in matrices-like tests: Raven’s APM scores increase significantly on repeated testing without any targeted training (e.g., Bors & Vigneau, ...
Dolphin 613 Motorboat's user avatar
8 votes

Do stimulants increase the IQ tests score for everyone?

IQ in ADHD sufferers indeed increases with the treatment of stimulants, such as methylphenidate (Meyes et al., 1994). This is thought to rely on the attention-narrowing effect of stimulants, i.e., ...
AliceD's user avatar
  • 20.6k
7 votes
Accepted

Why Bayesian Cognitive Modeling?

Here's a quick answer from general background knowledge, not from any specific knowledge of "Bayesian Program Synthesis (BPS)" In general, Bayesian models can use strongly informed priors or diffuse "...
John K. Kruschke's user avatar
7 votes

What is the meaningful difference between someone with a 145 IQ compared to a 100 IQ?

Consider, a normal IQ score falls between the range 85-115 which is approximately 70% of the population (and only 15% of people have an IQ of 115 or above), while an extended average IQ range tends to ...
xMathFanx's user avatar
7 votes

What is the rationale for the normal distribution of intelligence?

Short answer IQ scores are distributed normally, because they follow the central limit theorem. Background When we measure IQ scores in sufficiently large populations, they will be normally ...
AliceD's user avatar
  • 20.6k
7 votes
Accepted

How is the g-factor of intelligence calculated?

PCA or EFA: A standard approach to calculating a g factor would be to use principal components analysis (PCA) or exploratory factor analysis (EFA). Basically, you administer a broad battery of ...
Jeromy Anglim's user avatar
7 votes

Is there a theoretical maximum for IQ?

There are a few ways that you could answer this question. First, IQ is defined with a mean of 100 and a standard deviation of 15. But this is a normative score and relative to a given target ...
Jeromy Anglim's user avatar
6 votes
Accepted

What is the correlation between self-rated and objective measures of intelligence?

The term you are looking for is self-assessed intelligence (SAI) (sometimes subjectively-assessed intelligence or self-estimated intelligence). The leaders in this field are Tomas Chamorro-Premuzic ...
Arnon Weinberg's user avatar
  • 19.6k
6 votes

Correlation between "mechanical aptitude" and IQ

Can you suggest me better literature? Am I using the wrong concepts? Are the references provided above "sufficient"? I recommend you take a step back and ask yourself what your question is, and ...
faustus's user avatar
  • 1,247
6 votes
Accepted

A doctor told me that cephalic index can be used to measure human intelligence, is it true?

No, the index and its correlation to intelligence is not strong. See the medchrome.com description on cephalic index: The underlying assumption of craniometry is that skull size and shape ...
tale852150's user avatar
5 votes

Do children inherit intelligence from their mothers and not their fathers?

The psychology-spot article mostly links to researches done on mice. Only three links are about human genetics. One is philosophical in nature, other two deal with mental retardation. This study says ...
Spero's user avatar
  • 404
5 votes

What is the scientific support for Einstein's claim about the negative effects of reading too much?

I think what Einstein had in mind is that in order to come up with original ideas one must keep a balance between knowledge and creativity, as already stated by Jeromy Anglim. In a paper titled "The ...
Roland Coeurjoly's user avatar
5 votes
Accepted

How can tacit knowledge be measured?

Short answer Because tacit knowledge is defined as knowledge we cannot describe, researchers apparently adopt a strategy of just interviewing and listening for signs of tacit knowledge, as far as I ...
AliceD's user avatar
  • 20.6k
5 votes
Accepted

Which computer video games can improve intelligence, barring Medal of Honor?

This paper by Shams, Foussias, et al. (2015) gives a good meta-analysis of studies that have been conducted on the effects of video games on intelligence. Some games described as improving cognition ...
optimizedp's user avatar
5 votes

Relationship between intelligence (IQ) and Big 5 Personality

We just published a meta-analysis on the correlations between personality and intelligence in Psychological Bulletin (Anglim et al, 2022, PDF): Anglim, J., Dunlop, P. D., Wee, S., Horwood, S., Wood, J....
Jeromy Anglim's user avatar
4 votes

Free online intelligence test with norm table, high reliability, and must be printable?

I just found out about ICAR. The International Cognitive Ability Resource is a public-domain assessment tool which aims to encourage the broader assessment of cognitive abilities in psychology ...
Jeromy Anglim's user avatar
4 votes

Why do men have greater variance than women in mental test scores?

I've heard two theories related to genetics. Mental traits are massively polygenic (many genes with tiny effects). Men (XY) do not have a duplicate X chromosome like women (XX), which means that ...
Cameron Brick's user avatar
4 votes

Does masturbation in men negatively affect cognitive processes?

Masturbation in men or women does not negatively affect cognitive processes As I pointed out in another question in Health.SE, masturbation was a diagnosable psychological condition until DSM II in ...
Chris Rogers's user avatar
  • 12.2k
4 votes
Accepted

Is the logic of "Herrnstein's syllogism" sound, and are its premises true?

Herrnstein's Syllogism, as shown above, comes from the 1971 article written for The Atlantic by psychologist Richard Herrnstein (Herrnstein, 1971). It argued that while socioeconomic status of ...
Eff's user avatar
  • 700
4 votes

Can a person be brilliant even though slow at resolving problems?

Even though this is an old post, I'll post what I found online. I found the accepted answer to be missing something. For me, the definition of intelligence includes (even) more than either processing ...
dasWesen's user avatar
  • 141
4 votes

Do hormonal factors cause a trend of lower IQ in women?

I don't think anybody wants to limit particular topics on here, but the point of the site is to discuss science. Science starts with empirical observation, rather than just anecdote. So the first flaw ...
splint's user avatar
  • 1,113
4 votes

Does night-sleep-deprivation have any effect on cognitive performance?

According to this article, yes it does have various symptoms including cognitive deficiencies that make us more prone to errors and less efficient : Circadian rhythms biologically program us to ...
DesignerAnalyst's user avatar
4 votes
Accepted

Are the "scientific" points made in the James Damore document factually accurate?

A few thoughts on those two pieces... Do women prefer working with people? Results on this are certainly debated. This article summarizes a study (linked in the article) that concludes women prefer ...
mflo-ByeSE's user avatar
  • 1,283
4 votes

Do stimulants increase the IQ tests score for everyone?

Not about IQ as a whole alas, but I found a 2010 systematic review & meta-analysis "Modafinil and methylphenidate for neuroenhancement in healthy individuals: A systematic review", apparently the ...
Dolphin 613 Motorboat's user avatar
4 votes
Accepted

Procedures behind establishing the IQ scale

Due to fact, that I can´t give a comment, I will post an answer, that is not sufficient. However, I hope this might give you little more insight. Furthermore, my knowledge mainly builds on german IQ ...
bucky's user avatar
  • 443
4 votes
Accepted

Do men, on average, have a higher general intelligence score?

There's a Wikipedia page with a lot of related studies. Among other things we find out there that: A 2004 meta-analysis by Richard Lynn and Paul Irwing published in 2005 found that the mean IQ of men ...
Dolphin 613 Motorboat's user avatar

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