defective, the problem is still more difficult. No
two persons have the same degree of intelligence. Some are clearly
lacking in mentality. Others are manifestly intelligent. The great mass
range all along between these extremes. Various arbitrary rules have
been laid down to aid in classifying different grades of defectives.
Generally the feeble-minded can be sorted out. The defectives are
supposed, if young, to be two years or more below the normal scholar in
development; if older, three or more below. Their standing is fixed by
asking certain test questions. Furthermore, a list of questions has
been commonly used for an "intelligence test." These queries have
nothing to do with the school work of the child, but are supposed to
reveal only his native intelligence.

No doubt in a broad way such tests throw considerable light on the
mentality of those who submit to the examination. Ordinary experience,
however, shows that they cannot be fully relied on. Some children
develop very slowly, others very rapidly. Some are much quicker, others
slower in their perceptions and responses. No two children or grown-ups
have the same turn of mind. One may be very bright in business affairs
and very dull in books. One may be clever in arithmetic and hopeless in
grammar. One may have marked mechanical ability and no taste for school.
These tests are only valuable if given by well qualified examiners, and
the method is so new that few have had the chance to thoroughly prepare
for the work. For the most part the tests are given by people who are
wholly unfit for so important a task.

Quite aside from all this it is not certain that intelligent people are
necessarily safer to the community than stupid ones. There is always a
tendency for the stupid to stick to the beaten path. Intelligence
generally means individuality and divergence. On the other hand, the
stupid and subnormal are moved much more directly by instincts and
emotions. Their lack of imagination, poor perceptions and want of
reasoning or comparing power, make their self-control weak. In sudden
stress or an unusual situation, they are easily swept away and respond
directly to instinct and feeling. In short the urge of the primitive
through the long history of the race cannot be modified sufficiently by
the new structure that civilization has built around more intelligent
people.

The various distinctions between the feeble-minded and the normal must
not be taken with too