isappears earlier in girls than in boys.

Differences between the sexes have been established also by means of
experimental psychology, based upon the examination of a very large
number of instances. Although it must be admitted that some of the
acquirements of this school are still open to dispute, the data of these
collective investigations must not be ignored. Berthold Hartmann has
studied the childish circle of thought, by means of a series of
experiments which are commonly spoken of as the Annaberg experiments.
Schoolboys to the number of 660 and schoolgirls to the number of 652, at
ages between 5-3/4 and 6-3/4 years, were subjected to examination. It
was very remarkable to see how in respect of certain ideas, such as
those of the triangle, cube, and circle, the girls greatly excelled the
boys; whereas in respect of animals, minerals and social ideas, the boys
were better informed than the girls. Characteristic of the differences
between the sexes, according to Meumann,[16] from whom I take these
details, and some of those that follow, is the fact that the idea of
"marriage" was known to only 70 boys, as compared to 227 girls; whilst
the idea of "infant baptism" was known to 180 boys as compared to 220
girls. The idea of "pleasure" was also much better understood by girls
than by boys. Examination of the memory has also established the
existence of differences between the sexes in childhood. In boys the
memory for objects appears to be at first the best developed; to this
succeeds the memory for words with a visual content: in the case of
girls, the reverse of this was observed. In respect of numerous details,
however, the authorities conflict. According to Lobsien, boys have a
better memory for numbers, words, and sounds. The same investigator
informs us that in girls the visual memory is distinctly better than it
is in boys, this indicating that girls' memory for objects is also
better; but Netschajeff, on the other hand, maintains that boys have a
better memory for objects perceptible by the senses. It is interesting
to note that certain variations have been shown to exist at different
ages. During the first years of school-life, boys' memories are in
general better than girls', this advantage persisting up to the age of
ten; from this time onwards until the end of the years spent in primary
schools, girls excel boys in the matter of memory, but especially at
ages of eleven, twelve, thirteen, and fourteen. Later