The great David Wechsler (author of the Wechsler Intelligence Scales) created the Wechsler Deterioration Index (WDI). This index was calculated by subtracting the sum of your scaled scores (calculated with reference to the peak age group: 20-34) on all the subtests that decline as a function of old age, from those subtests that hold up relatively well with old age, and then dividing by the sum of hold subtests.
WDI = (sum of hold tests – sum of don’t hold tests)/sum of hold tests
So if the sum of your hold subtests was 40, and the sum of your don’t hold subtests was 20, your deterioration index was said to be an astonishing 50%! The implication was that you lost half your intelligence.
This was a bit silly because the subtest scaled scores were at best an interval scale, not a ratio scale with a true zero point, so the use of percentages was misleading, but the concept was all the rage with clinicians in the middle of the 20th century.
The hold subtests were Vocabulary (word knowledge), Information (General Knowledge), Object Assembly (spatial relations), and Picture Completion (visual alertness). The don’t hold subtests were Digit Span (working memory), Similarities (verbal abstraction), Digit-Symbol (rapid eye-hand coordination) and Block Design (spatial analysis). Wechsler was careful to make sure both the hold and don’t hold subtests both included an equal number of verbal and performance (visual-motor) subtests because generally speaking verbal subtests hold up better with age so if not for this counter-balancing, naturally verbally gifted people would show a spuriously high degree of deterioration.
The formula was wildly popular because people who you’d expect to show a high degree of dementia such as alcoholics, schizophrenics and the elderly, all had huge WDIs.
Unfortunately, Wechsler died before James Flynn managed to popularize what would come to be known as the Flynn effect. The fact that performance on IQ tests had been rising over the 20th century.
Thus Wechsler probably went to his grave thinking that old people did bad on don’t hold tests because they had suffered mental deterioration, not realizing it may instead have been because their generation was always bad at those tests, even when they were young. In order to determine which subtests really do and don’t hold with age, you would need to do a longitudinal study of adults who took the WAIS both at their prime and in old age, or at the very least, you would need to adjust age declines in scores for the Flynn effect, which some scholars have tried to do.
Nonetheless in 1992, the original WDI made a comeback when it came to diagnosing ADHD when it was noticed that these tend to have high WDIs.
Fossilized flora evidence suggests the presence of paleoforests up to latitudes of 85° in both Northern and Southern hemispheres.
we’re centuries away from that even if the whole world were using coal for its electricity and sasol for its petrol.
so yes. it is conceivable that man could warm the planet up to too warm…
but he’d really have to try!
I took the wais 4 not the wais one so the way I fit it together cannot be right:
0.117 = (51 – 41)/51
I did deteriorate after highschool.
Too much emotional trauma.
But at least I know it wasn’t autism.
My mom is retarded.
And I had no friends.
But I’m better now.
Doctors don’t really help people.
At least they didn’t help me.
so what’s the big deal?
“global warming” serves the same purpose for environment-al-ism that pc-ism serves for socialism.
it’s the permitted protest. it’s so permitted that capitalists promote it.
it’s smooshing up against the wall.
the wall that won’t allow two things…
1. coerced family planning. (although tfrs have fallen below replacement in many developing countries.)
2. the big one.
capitalism cannot be questioned.
one must assume it’s the best thing since circumcision.
off with your head!
trumpista zizek says…
chomsky’s take on trump pre-election was conspicuously un-condemnatory.
the whole thing is worth watching.
btw, the answer to zizek’s question is…
scandinavia is far from perfect, but…
it’s further along the road to perfection than any other countries.
which is funny considering they were the motherfuckers of europe for 500 years.
Ok, Pumpkin, I might have figured out the similarities spiel. Please tell me if my spiel is correct or incorrect.
Scores 12-19 are supposed to regress, if regression doesn’t happen, and if you haven’t looked up any answers online before the second test, and you score increased, it’s probably measurement error, or it’s that you didn’t show your full potential on the first trial. It’s very rare for this to happen, so it seems plausible.
Now, if you add up the scores from different tests, you get a real score. If that real score is 12 or above, the gains might just be from intellectual gains, error of measurement, or you not showing your full potential on the first try.