The g factor (also known as general intelligence, general mental ability or general intelligence factor) is a construct developed in psychometric investigations of cognitive abilities and human intelligence. It is a variable that summarizes positive correlations among different cognitive tasks, reflecting the fact that an individual's performance on one type of cognitive task tends to be comparable to that person's performance on other kinds of cognitive tasks. The g factor typically accounts for 40 to 50 percent of the between-individual performance differences on a given cognitive test, and composite scores ("IQ scores") based on many tests are frequently regarded as estimates of individuals' standing on the g factor. The terms IQ, general intelligence, general cognitive ability, general mental ability, and simply intelligence are often used interchangeably to refer to this common core shared by cognitive tests. The g factor targets a particular measure of general intelligence.
The existence of the g factor was originally proposed by the English psychologist Charles Spearman in the early years of the 20th century. He observed that children's performance ratings, across seemingly unrelated school subjects, were positively correlated, and reasoned that these correlations reflected the influence of an underlying general mental ability that entered into performance on all kinds of mental tests. Spearman suggested that all mental performance could be conceptualized in terms of a single general ability factor, which he labeled g, and many narrow task-specific ability factors. Soon after Spearman proposed the existence of g, it was challenged by Godfrey Thomson, who presented evidence that such intercorrelations among test results could arise even if no g-factor existed. Today's factor models of intelligence typically represent cognitive abilities as a three-level hierarchy, where there are many narrow factors at the bottom of the hierarchy, a handful of broad, more general factors at the intermediate level, and at the apex a single factor, referred to as the g factor, which represents the variance common to all cognitive tasks.
Traditionally, research on g has concentrated on psychometric investigations of test data, with a special emphasis on factor analytic approaches. However, empirical research on the nature of g has also drawn upon experimental cognitive psychology and mental chronometry, brain anatomy and physiology, quantitative and molecular genetics, and primate evolution. Some scientists consider g as a statistical regularity and uncontroversial, and a general cognitive factor appears in data collected from people in nearly every human culture. Yet, there is no consensus as to what causes the positive correlations between tests.
Research in the field of behavioral genetics has established that the construct of g is highly heritable. It has a number of other biological correlates, including brain size. It is also a significant predictor of individual differences in many social outcomes, particularly in education and employment. The most widely accepted contemporary theories of intelligence incorporate the g factor. However, critics of g have contended that an emphasis on g is misplaced and entails a devaluation of other important abilities. Stephen J. Gould famously denounced the concept of g as supporting an unrealistic reified view of human intelligence.
German Wikipedia mentions that the g factor is one of the causes of the Lamb Shift. It does not say why and I am trying to find a connection between these two things. Any ideas?
I'm reading peskin QFT textbook. In page 196 eq. (6.58) it says
$$F_2(q^2=0)=\frac{\alpha}{2\pi}\int ^1_0 dx dy dz \delta (x+y+z-1) \frac{2m^2z(1-z)}{m^2(1-z)^2}\\=\frac{\alpha}{\pi}\int ^1_0 dz\int ^{1-z}_0 dy \frac{z}{1-z}=\frac{\alpha}{2\pi}$$
I confirmed the conversion from the first line...
I'm reading the book Quantum Field Theory and the Standard Model by Matthew Schwartz and currently I'm studying the chapter 17 titled "The anomalous magnetic moment" which is devoted to computing the corrections due to QFT to the g factor.
My main issue is in the beginning of the chapter, where...
https://link.springer.com/chapter/10.1007/978-3-540-39664-2_1
http://iopscience.iop.org/article/10.1088/0031-8949/1988/T22/016/pdf
In these two experiments done back in the 80's, electrons were trapped inside a penning trap for long periods of time. They were measuring the ratio of the magnetic...
I was just going through the calculation to go from the top line to the bottom and was just not arriving at the same result. Working backwards and just looking at the first term (i.e. the one with coefficient ##g_L## I get):
## \frac {J^2 + J + L^2 + L - S^2 - S}{2(J^2 + J)} = \frac {L^2 + S^2...
Hi, last week I read Rabi's paper "The Molcular Beam Resonance Method".
This paper contains the basic idea of the oscillation which we call "Rabi Oscillation" as many of you guys know.
However, at the end of this paper, Rabi calculates nuclear magnetic moments of Li (atomic mass 6), Li (atomic...
Hi, last week I read Rabi's paper "The Molcular Beam Resonance Method".
This paper contains the basic idea of the oscillation which we call "Rabi Oscillation" as many of you guys know.
However, at the end of this paper, Rabi calculates nuclear magnetic moments of Li (atomic mass 6), Li (atomic...
revision
already calculated J to be 15/2
have already found g to be 1.33
M = ngμJ
magnetic suseptibilty is 5X10^-7 m^3/mol
please could omeone tell me if it is possible to calculate the magnetic susceptibility from the above information? thanks in advance for an pointers.
Homework Statement
A source which emits a line at 500 nm is found to exhibit the normal Zeeman effect
when placed in a magnetic fi eld. Calculate the magnetic field given that the separation
of adjacent components in the Zeeman pattern is 12.0 pm.
Homework Equations
E=hc/lambda...
Homework Statement
I was looking the calculation of Landé g factor. It starts with
\mu=-\frac{e}{2m_{e}} (\vec{L}+2\vec{S}) assuming that g of electron =2
The lecture notes then proceed by calculating g=1+\frac{J(J+1)+S(S+1)-L(L+1)}{2J(J+1)} using the cosine rule.Homework Equations
the...
In quantum mechanics, magnetic moment is equal to g factor times (gyromagnetic ratio x angular momentum). For orbital angular momentum, g=1, for electron spin angular momentum, g=2, for proton, it is 3.56. Is there any physical significance for this factor? why scientist introduce this factor...
Homework Statement
Deduce the expression of Lande g factors from Zeeman effect
Homework Equations
For Zeeman effect, we treat the energy perturbation as \vec{S}\cdot\vec{L}, where S is the spin and L is the orbital momentum. Let magnetic field along z direction so the energy correction...