The Corpus Callosum

Smarter People Get Demenia Faster

has an article about a study that shows a relationship between the
amount of eduction a person has, and how rapidly memory loss occurs
when they get senile dementia of the Alzheimer type (SDAT).
 The more education a person has, the faster the memory loss
occurs. (Higher
Education Delays Dementia Onset but Is Linked to More Rapid Progression
free registration required)

At first this seems counterintuitive.  But think about it.

of memory, I remember when I was in college, there was a newspaper
article about a kid who did a science project on the freezing of water.
 He showed that hot water freezes faster than cold water.

To understand, in case it is not obvious, think of
it this way:  If you put water in a freezer, the rate at which
water cools is determined primarily by the surface area and the
temperature difference (gradient).  All other things being
hotter water will lose more heat per second than cold water will.
 That is what is meant by the phrase “freezes faster:” more
heat is lost per second.  But the hot water has
farther to go
before it actually freezes.  So even
though the rate of freezing is higher, it
takes longer to freeze
.  The hot water has to lose
more heat in order to freeze, so even though the rate is higher, the
time required is also higher.  Even thought the process occurs
at a higher rate, it still takes longer.

So there really is nothing to worry about if you have many years of
post-high-school education.  It does not mean that you will
get dementia sooner, just that it occurs faster.

Indeed, the same study showed that, on average, more education is
correlated with a greater delay in onset.


  1. #1 Greg P
    October 31, 2007

    Not to throw water on your analogy, but my take on this is that, by the time a person with a higher level of education/intelligence (not always the same thing) shows signs of dementia, they are really in an advanced state, so much nearer the end stages of Alzheimer’s.

    All patients with mild dementia are able to compensate in some way, many by being more quiet, withdrawn, evasive, argumentative. But just as with focal deficits in stroke, there are ways to compensate for specific problems, and a more educated person is more likely to find these ways on their own. Aside from the diffuse nature of the process, Alzheimer’s especially in early stages is a multifocal problem, so there may be quite functionally intact areas of the brain.

    The ways that we have for deciding whether someone has cognitive deficits don’t really take into account educational level or intelligence, unless you have previous results for comparison. So everyone gets compared to the “average” person.

  2. #2 Ian
    November 2, 2007

    This seems to contradict the findings of Snowden’s “Nun study”

    as I recall from Brain and Behavior (a course I took nearly 20 years ago so I’ll be more than a little tentative with my truth), “better” educated nuns were less likely to display symptoms of Alzheimer’s although, on post-mortum, they found as much or more plaque than their less educated cohort.

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