Trends in Gender Differences in Acad em ic
Ach ievemen t from 1960 to 1994: An Analysis of
Differen ces in Mean , Varian ce, and Extrem e
and Larry V. Hed ges
The University of Chicago
G en der differences in academ ic achievem ent have been studied exten sively.
While it is gen erally agreed that females have a slight advantage on average
in v erb al abili ties an d m ales h ave a sligh t advan ta ge on average in
mathematics, it is unclear whether these differences have chan ged over tim e.
In this paper eviden ce from seven surveys representative of the United States
twelth grade student popu lation an d the National Assessment of Education al
Progress (NAEP) long term trend data is brou ght to bear on the magnitude
of gender differences in achievem ent, the level of agreem ent am ong different
indices of difference, and the stability of these differen ces over tim e. These
data provide the unique opportu nity to not on ly em pirically estimate mean
differences, differences in variance, an d differences in extreme scores, bu t also
to estimate ch ange over time in all three indices using both the sam e and
different tests over tim e. Results show that gender differences in mean an d
varian ce are small, while differences in extrem e scores are often substantial.
None of these differences have changed significantly sin ce 1960, with the
possible exception of mean differences in mathem atics an d science. Each of
the datasets reflects the racial com position of the national popu lation wh en
properly weighted (i.e. White = 70% , Black = 15% , Hispan ic = 10% , Other
= 5% ).
The lite rature on gender differe nce s in acade mic achie vement is exte nsive ,
howe ve r, despite all the work that has be en done, rese archers have reache d
Sex Roles, Vol. 39, Nos. 1/2, 1998
1998 Pl e num Publishing Cor porati on
To whom correspond en ce should be addre sse d at The University of Chicago, De partmen t
of Education, 5835 S. Kimbark Ave., Chicago, IL 60637.