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Reading & Use
Succeed in LRN - Level C2 - Practice Test 1

Part 1

Read the text below about The Brain and IQ and then answer the questions that follow.
For questions 1-9, choose the best answer (A, B or C).
est 1 Debate has long raged amongst scientists as to the correlation between brain size and IQ. For German

The Brain and IQ
Practice T anatomist, Friedrich Tiedemann, there was no cause for debate. In 1836 his stance on the issue was unequivo-

cal. In the journal of Philosophical Transaction, Tiedman confidently asserted: ‘There is undoubtedly a connection
between the absolute size of the brain and the intellectual powers and functions of the mind.’

However, such speculative statements cut no ice in scientific circles today. Watertight empirical evidence is
required to support theory and conjecture. Advances in brain imaging methods, such as MRI scans, have now
enabled scientists with far greater accuracy to determine if brain volume determines IQ. This is because scans
can make more reliable assessments of brain volume than ever before.

Aided by such advances in MRI technology, scientists from the University of Vienna have studied data from
148 samples comprising 8,000 participants. A robust but weak connection was established between brain size
and IQ, regardless of a participant’s sex and age.

‘The presently observed association means that brain volume plays only a minor role in explaining IQ test per-
formance in humans,’ explains Jakob Pietschnig from the Institute of Applied Psychology of the University of
Vienna. ‘Although a certain association is observable, brain volume appears to be of only little practical rele-
vance. Rather, brain structure and integrity appear to be more important as a biological foundation of IQ,
whilst brain size works as one of many compensatory mechanisms of cognitive functions.’

The importance of brain structure compared to brain volume becomes evident when comparing different
species. For example, the sperm whale has the largest central nervous system including its brain and when
controlling for body mass, the shrew tops the list, with humans trailing far behind. This suggests differences in
brain structure appear to be mainly responsible for between-species differences in intelligence.

According to Dr. Pietschnig: ‘Structural aspects appear to be more important for cognitive performance within
humans as well.’ It should, therefore, pose no concern for smaller-brained females that males surpass them in
brain volume. Indeed whilst men have larger brains than women, there are no differences in global IQ test
performance between the sexes.

Further evidence that bigger does not necessarily equate with better, when it comes to brain size, is proved
fairly conclusively in individuals with megalencephaly syndrome. Sufferers characteristically have an abnormal-
ly large brain although this is invariably inversely proportional to IQ.

It is similarly worth noting that Einstein, the most celebrated genius of the twentieth century, had a brain no
larger than average. But that is where the similarity between Einstein’s brain and that of mere mortals ends.
For the integral structure of Einstein’s brain was characterised by unusually high numbers of synaptic connec-
tions and an extraordinarily large area of tissue linking the right and left hemispheres of the brain, known as
the corpus callosum. So brain structure, and seemingly not mass, was the key to genius, as Pietschig’s findings
would have predicted.

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