IQ data in a time capsule

The discovery of lost IQ data from school children in
the 1930s and 1940s has provided a unique insight into the
relationship between lifestyle, ageing and cognitive decline. This
research is especially significant as it offers a way of comparing
the early mental ability of some of the original participants with
their cognitive function today, more than sixty years
on.

The differences in performance across the ages confirm that, as
suspected, some of the age-related inability to think straight is
self-inflicted. Some researchers even believe that following a
healthy diet and lifestyle may prevent half of all cases of
dementia. The original IQ data was collected by the Scottish
Council for Research in Education in both 1932 and 1947. The
ledgers, recorded in beautiful copperplate handwriting, lay
mouldering in a basement, wrapped in brown paper and tied with
string, until rediscovered by Lawrence Whalley, Professor of Mental
Health, University of Aberdeen; he was acting on a tip from Ian
Deary, Professor of Differential Psychology at the University of
Edinburgh, who found a lucky reference to the forgotten study in an
obscure book.

The Scottish Mental Survey tested every 11-year-old in Scotland,
obtaining data on 89,498 children in 1932 and 70,805 children in
1947. The motivation at the time was a concern that the IQ of the
nation was declining. This extraordinary data now provides a way of
studying the effects of aging on thought processes and
understanding ­ something psychologists refer to as cognitive
ability.

Over the last decade, 1,500 of these original pupils have been
tracked down in an attempt to discover the factors that help to
preserve wisdom and mental ability over a lifetime. All agreed to
be retested with modern IQ tests, plus the original exam they sat
at the age of 11. On one occasion, 101 participants resat the test
exactly 66 years on to the very day. They were also asked questions
about their dietary and lifestyle habits over the last 60 years and
had an MRI scan to assess their degree of brain shrinkage.

Examples of some of the mental ability test questions asked in
1932:

1. If 19d is the same as 1/7 write G, if not write R.


2. Fin is to fish as wing is to (feather, air, bird, sail,
   herring).


3. Tragu’ is cheaper than vashol’ and vashol’ is
   dearer than spongop.’ Which is the dearest?


4. Underline the different’ word in (eye, pen, nose, chin,
   ear).


5. Three posts are at the corners of an equilateral, that is an
   equal-sided triangle. From where I am standing, the post nearest to
   me seems to be exactly half-way between the other two. If I now
   take two sidesteps to the left, will the posts look like this:
   I    I I or like this I I    I?

People who retain a higher IQ score tend to be those with more
active social lives, who eat a nutritious diet and remain
physically active. An unhealthy diet and lifestyle is associated
with an age-related decline in cognitive ability of as much as 10%,
with women tending to experience more cognitive decline than men.
The factors most associated with a fall in IQ as people age
are:

• Eating a diet that is high in fats, salt and sugar and low in
  fruit, vegetables and fibre.


• Smoking cigarettes


• Poor sociability


• High blood pressure


• Raised cholesterol levels


• Obesity

 

It’s not all bad news, however, as the results also suggest
ways in which we may help to halt cognitive decline as we get
older.

Eat more oily fish: Good intakes of omega 3 fish oils
enhance metal ability.

Science suggests that we evolved from the sea, so it is perhaps not
surprising that two long-chain omega 3 polyunsaturated fatty acids
found in fish oils are important for both brain structure and
function. Docosahexaenoic acid (DHA) is incorporated into brain
cell membranes at the communication gaps (synapses) where they
improve membrane fluidity and allow messages to pass more swiftly
from one brain cell to another. In contrast, eicosapentaenoic acid
(EPA) appears to play  a functional role in improving cell
signalling. When the brain is low in DHA and EPA, messages travel
less efficiently and people  with Alzheimer’s have been
found to have lower concentrations of DHA in their brain.

Cut back on unhealthy fats: A diet high in saturated
fat increases the risk of obesity and diabetes, both of which
contribute to mental decline.

Don’t add salt to your food: Increased
consumption increases blood pressure, which in turn raises dementia
risk.

Ensure good intakes of folic acid and vitamin B12:
These vitamins are important for nerve function and to prevent one
form of anaemia. They are also needed to process the amino acid,
homocysteine, which is linked with hardening and furring up of the
arteries, cerebrovascular disease and dementia.

Stay physically active: Regular physical exercise helps
to reduce the risks of dementia and memory problems. Some
participants ­ those who had high levels of fitness ­
actually enjoyed an increase in IQ score over the years.

Stay mentally active: Those who seek out intellectual
stimulation also enhance brain function by promoting the formation
of new connections between brain cells.

Don’t smoke: Smoking cigarettes damages brain
cells, reduces blood circulation to the brain and contributes to
declining IQ with age. It may also contribute to mental decline by
damaging the connections between different parts of the brain. As a
result, smoking throughout your life lowers IQ by around 2%.

Supplements

The nutritional supplements most likely to help combat
age-related cognitive decline are:

• Folic acid


• Vitamin B12


• Omega 3 fish oils

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