has been responsible for diagnosing the twins into
identical and fraternal
groups and has personally collected most of the data
physical resemblances and differences.
The actual administration of intelligence and
personality tests was
carried out by a considerable group of assistants who
had received their
training under Dr. Freeman. Dr. Newman has been chiefly
the discovery of the cases of identical twins reared
apart and has made
arrangements for having them come to us for study. He
is also responsible
for obtaining the life-histories of all but one of
these interesting pairs.
Tentative reports on the first nine pairs were written
for the Journal of
Heredity by Dr. Newman with the co-operation of Dr.
Freeman. These re-
ports, together with those of ten new cases not
previously reported, have
been worked over by Drs. Newman and Freeman in
The general conclusions discussed in the final chapter
represent a con-
sensus of the views of all three authors arrived at
after considerable dis-
cussion of divergent interpretations of the data. In
this chapter we have
attempted, first, to give a summary of the facts
themselves in as objective
a manner as possible, and, second, to draw up a
statement of interpretation
which is sufficiently guarded to be acceptable to those
having a somewhat
different bias toward the problem.
Grateful acknowledgments are herewith made to all those
given of their time and energy to this investigation.
Especially do we wish