strong--that due to social opinion. We constantly modify our
memories to agree more closely with the truths of social belief,
paring down unconsciously the difference between our own and others'
reports of things. If several witnesses of an event be allowed to
compare notes from time to time, they will gradually come to tell more
nearly the same story.

The other curve (II) in the figure, that secured by the method of
Identification, seemed to the investigators to be the most accurate.
It is not subject to the errors due to expression and to contrast, and
it has the advantage of allowing the subject the right to recognise
the square. It is shown to him again, with no information that it is
the same, and he decides whether from his remembrance of the earlier
one, it is the same or not. The only objection to this method is that
it requires a great many experiments in order to get an average
result. To be reliable, an average must be secured, seeing that, for
one or two or a few trials, the student may guess right without
remembering the original square at all. By taking a large number of
persons, such as the three hundred students, this objection may be
overcome. Comparing the averages, for example, of the results given
by the men and women respectively, we found practically no difference
between them.

This last point may serve to introduce a distinction which is
important in all work in experimental psychology, and one which is
recognised also in many other sciences--the distinction between
results obtained respectively from one individual and from many. Very
often the only way to learn truth about a single individual is to
investigate a number together. In all large classes of things,
especially living things, there are great individual differences, and
in any particular case this personal variation may be so large that it
obscures the real nature of the normal. For example, three large sons
may be born to two small parents; and from this case alone it might be
inferred that all small parents have large sons. Or three girls might
have better memories than three boys in the same family or school, and
from this it might be argued that girls are better endowed in this
direction than boys. In all such cases the proper thing to do is to
get a large number of cases and combine them; then the preponderance
which the first cases examined may have shown, in one direction or the
other, is corrected. This gives rise to what is