Why Do the Achievement Gaps Exist?
Scholars Provide an Overview of Explanations for
Black-White Test Score Gap
Many explanations exist for why black Americans consistently
score lower on achievement and intelligence tests than white
Americans. Two scholars provide an overview of these
This reports some of the ideas
and findings from the following source:
Jencks, C., & Phillips, M. (1998). The black-white
test score gap: An introduction. In C. Jencks and M.
Phillips (Eds.),The black-white test score
gap(pp. 1-51). Washington, DC: Brookings Institution.
To see other reports that originated from this same
citation, go to the bibliography.
Christopher Jencks and Meredith Phillips say that Americans
have been aware of a gap in black-white test scores since
World War I. They say that while a number of explanations for
this gap have been put forward, none of them is completely
Jencks and Phillips review both the theories of why the gap
persists and also the research that bears on these
Four Kinds of Explanations for the Black-White Test Score
Jencks and Phillips describe four kinds of explanations for
the test score gap:
Within each type of explanation are different theories.
Jencks and Phillips point out that some theories have more
research support than others.
Different Theories and
Jencks and Phillips describe four explanations of
Labeling bias. Labeling bias occurs
when tests claim to measure one thing but
really measure another. Jencks and Phillips
say that most psychologists agree that IQ
tests measure developed ability rather than
innate ability—although the tests
supposedly measure innate ability. Because
developed ability depends heavily on
environmental characteristics, groups that
live in disadvantaged environments will
score lower. The problem here is over what
is being measured.
Content bias. Content bias exists
when a test measures knowledge that is
relevant only for a particular group. So,
for instance, a test that measured
knowledge of "white" culture vocabulary
would put black students at a disadvantage
(assuming that "white" and "black"
vocabulary were significantly different).
Jencks and Phillips say that most tests do
not test familiarity with any particular
culture. Also, even on tests not confined
to exposure to "white" culture or language
(for instance, mathematics) black students
still score consistently lower than white
Methodological bias. Methodological
bias exists when the way the test is given
or scored puts one group at a disadvantage.
So, for instance, if black students scored
lower on the same tests when they were
given by white (as opposed to black)
testers, we would suspect methodological
bias. Jencks and Phillips say that this
does not appear to be the case with regard
to the black-white test score gap.
Prediction bias. Tests are
often used to forecast a student or
worker's future performance. Prediction
bias would be present if a test, like the
SAT, underestimated one group's future
performance. However, say Jencks and
Phillips, research indicates that black and
white students who score the same on the
SAT do not perform the same in college.
Rather, the SAT appears
to overestimate the college
performance of black students (blacks in
college do worse than whites with the same
SAT scores). Research also indicates that
black workers get slightly lower ratings
from their supervisors than white workers
with the same test scores.
Jencks and Phillips say that the argument over
the genetic or hereditary component of
intelligence has raged throughout most of the
twentieth century. Many studies have been done to
try to tease out the effects of heredity on
intelligence. Jencks and Phillips say that while
heredity clearly plays some part, the research is
still unclear on just how important it is. They
say that research on racially mixed children,
research on black children raised in white homes,
and research on racially mixed children in other
countries provide three tentative conclusions:
Black or mixed-race children raised in
white households have higher test scores
than black or mixed-race children raised in
When "black" genes (genes that indicate
African descent) are not visible to the
naked eye, they do not appear to have much
effect. In other words, children who have a
black parent, grandparent, or ancestor, but
who look white and live within a white
community, do not have lower test scores
than whites from completely European
In America, when black children raised in
white homes reach adolescence, their test
scores drop (indicating a change in
environment rather than a change in the
students' innate abilities).
Jencks and Phillips conclude that:
". . . we find it hard to see how anyone
reading these studies with an open mind could
conclude that innate ability played a large
role in the black-white gap." (p. 20)
Jencks and Phillips say that trying to tease out
family background effects from other kinds of
effects is a "statistical nightmare." Family
background characteristics are related to many
other characteristics and so it is difficult to
tell what is really causing the effect. They
describe different explanations and the research
Parental schooling. The education gap
between white and black mothers has fallen
over the course of the twentieth century.
Correspondingly, the test gap between their
children has closed as well. The effect of
mothers' education does not appear to be
very large, however. Differences in black
and white fathers' level of education
appears to have even less impact on their
children's test scores.
Income effects. White parents tend to
make more money than black parents. Does
this explain the test score gap? Jencks and
Phillips think not. According to research,
once parental schooling, test scores, and
family background are taken into account,
the effects of income differences between
black and white parents becomes quite
Single-parent families. Jencks and
Phillips say that the effects of being
raised in a single-parent family are "never
large enough to be of any substantive
importance" (p. 24) once other family
characteristics are taken into account.
Parenting strategies. "Parenting
practices appear to have a sizeable impact
on children's test scores," say Jencks and
Phillips (p. 24). Even when other family
characteristics are taken into account,
differences in parenting practices account
for between 20% and 25% of the black-white
test score gap.
Grandparents. Even when black and
white parents make the same income, black
parents were more likely to have been
raised in disadvantaged families. Research
shows that the disadvantaged status of
black children's grandparents is associated
with lower test scores.
Jencks and Phillips describe different cultural
explanations for the test score gap.
Fear of "acting white." Jencks and
Phillips say that an influential article in
the mid-1980s found that academically
successful black students were disparaged
by their black peers for acting "white."
So, the argument goes, black students may
not try to achieve for fear of being teased
by their peers. Jencks and Phillips say
that later research casts doubt on the
importance of this fear for black students.
They say that academically successful white
students might also be teased for being
"nerds." Being academically successful has
both social costs and benefits for black
and white students. Also, a study of
academically successful students found that
blacks tend to benefit from this success
more than whites.
Getting A's in math was almost
completely unrelated to feeling
unpopular, being physically
threatened, or being put down by
other students. Indeed, honor society
students were likely to feel more
popular and less likely to feel
The social costs and benefits of good
grades were about the same for black
and white students. Indeed, black
students seemed to benefit more than
their white peers from academic
One critique of this research says that while
the fear of "acting white" probably does not
have much to do with creating the test
score gap, it may be important in
understanding why black students do
not reduce the gap.
Stereotype threat. Another
explanation says that black students may
underperform because they are threatened by
the stereotype that blacks are not as
"smart" as whites. That is, the anxiety
over the stereotype that blacks are not
academically successful may impair black
students' performance. Jencks and Phillips
say that this explanation was supported by
an ingenious series of experiments. The
study found that when black students were
asked to record their race before they took
a test, they tended to make lower scores.
Black students also made more mistakes when
the test was described by the experimenter
as testing "verbal reasoning ability."
White students' test scores did not change
under either circumstance.
Jenks and Phillips say that none of the current
explanations tells all there is to know about the
black-white test score gap, nor do they all point to a
single way of closing that gap. They go on to suggest that
the U.S. ought to be conducting large-scale experiments to
better understand the black-white test score gap.
According to Jencks and Phillips:
"If we did more experiments, we might eventually
develop better theories. At present, theorizing about
the causes of the black-white gap is largely a waste of
time, because there is no way to resolve theoretical
disagreements without data that all sides accept as
Research Design: Authors Christopher Jencks
and Meredith Phillips review theories and research on the
black-white test score gap. They also comment on effects of
the gap and what things might be done to narrow it.