Yesterday The New York Times reported:

Dr. Jackson said that despite expressions of concern, a cognitive test was not indicated for Mr. Trump and he had not planned to conduct one at the Walter Reed National Military Medical Center in Bethesda, Md., where the president underwent his annual physical on Friday.

“This has been the narrative for a while. He saw doing the physical as an opportunity to put some of that to rest,” Dr. Jackson said during a nearly hourlong question-and-answer session in the White House briefing room. “He actively asked me to include that in it, so we did.”

Dr. Jackson said that Mr. Trump received a score of 30 out of 30 on the Montreal Cognitive Assessment, a well-known test regularly used at Walter Reed and other hospitals.

The test is described as a “rapid-screening instrument for mild cognitive dysfunction” that focuses on “attention and concentration, executive functions, memory, language” and other mental skills. It asks patients to repeat a list of spoken words, identify pictures of animals like a lion or a camel, draw a cube or draw a clock face set to a particular time.

Dr. Jackson said the president did “exceedingly well” on the screening test, adding evidence to the doctor’s own assessment that the president has been “very sharp” during numerous interactions he has had with him during the past year.

Psychiatric experts said the brief, 10- to 15-minute screening test is not comprehensive and might not catch all patients with early stages of dementia. Dr. Bandy Lee, the author of “The Dangerous Case of Donald Trump,” which expresses concern about the president’s mental health, said in a brief interview that the president requires a full, detailed neuropsychiatric evaluation.

However, Dr. Jackson said he had observed Mr. Trump closely, often several times a day, for the past year, and was satisfied that the Montreal test is “sensitive enough” to have picked up serious cognitive issues if they were present.

In order to convert Trump’s perfect score of 30/30 to IQ,  I found a study that tried to norm the Montreal Cognitive Assessment.   The norms showed that Trump scored 1.82 standard deviations (SD) above the mean for his 70+ age group, implying an IQ of 127+ since each standard deviation above the mean on the IQ scale equals 15 points above 100.

However as the table below shows, the sample was overwhelmingly non-white , and IQ has traditionally been normed with reference to the white population.  Unfortunately the samples were too small to provide norms specifically for whites in Trump’s age group but from the table below we can calculate that being +1.82 SD with respect to total norms equals +1.74 with respect to white norms.  Assuming the same holds in Trump’s age group and assuming he legitimately scored perfect on this test (no monkey business),  it implies an IQ of  126+ (white norms).

In the past I’ve estimated Trump’s IQ to be as high as 125, but it looks like he’s at least that smart, and possibly much smarter, since the Montreal Cognitive Assessment doesn’t measure beyond 126+ in Trump’s cohort, and it’s tempting to add a 5 point bonus because many of the dullest folks in Trump’s birth cohort are excluded from these norms because of death, poor health and impairment.  If all had survived and been tested the average score would have been lower, thus making Trump perhaps 5 points smarter.  On the other hand, the standard deviation of the raw scores might be deflated by the mean being so close to the ceiling, thus inflating Trump’s IQ 5 points.  These two biases likely cancel each other out.