1. SOCIAL-CLASS AND ETHNIC DIFFERENCES IN IQ
SOCIAL CLASS EFFECT: CHILDREN FROM LOWER AND
WORKING CLASS HOMES HAVE 10 TO 15 POINTS BELOW
THEIR MIDDLE CLASS AGE-MATES ON STANDARDIZED IQ TEST
(HELMS, 1997)
THERE ARE ALSO SOME ETHNIC VARIATIONS IN
INTELLECTUAL PERFORMANCE
In the US, children of African American and native American
ancestry score on average 12 to 15 points below their
European American classmates on standardized IQ test.
Different ethnic groups may also display distinctive ability
profiles.
The fact is that we cannot predict anything about the IQ or
the future accomplishments of an individual on the basis of
ethnicity or skin colour.

2. WHY DO GROUPS DIFFER IN INTELLECTUAL PERFORMANCE?
3 GENERAL HYPOTHESES TO ACCOUNT FOR ETHNIC AND
SOCIAL-CLASS DIFFERENCES
A-CULTURAL/TEST-BIAS HYPOTHESIS
B-GENETIC HYPOTHESIS
C- ENVIRONMENTAL HYPOTHESIS
1.THE CULTURAL/TEST-BIAS HYPOTHESIS
-THAT STANDARDIZED IQ TESTS AND THE WAYS THEY ARE
ADMINISTERED ARE GEARED TOWARD WHITE, MIDDLE-
CLASS CULTURAL EXPERIENCES AND UNDERESTIMATE THE
INTELLECTUAL CAPABILITIES OF ECONOMICALLY
DISADVANTAGE CHILDREN ESPECIALLY THOSE FROM
MINORITY SUBCULTURE
- THOSE WHO FAVOR THIS HYPOTHESIS BELIEVE THAT
GROUP DIFFERENCES IN IQ ARE ARTIFACT OF TESTS AND
TESTING PROCEDURES

3. DOES TEST-BIAS EXPLAIN GROUP DIFFERENCES IN IQ?
SEVERAL ATTEMPS HAVE BEEN MADE TO CONSTRUCT
‘CULTURE FAIR’ IQ TESTS THAT DO NOT PLACE PEOPLE AT AN
IMMEDIATE ADVANTAGE (FAGAN, 2000).
TAKEN TOGETHER, THESE FINDINGS IMPLY THAT GROUP
DIFFERENCES IN IQ SCORES ARE NOT SOLELY ATTRIBUTABLE
TO BIASES IN THE CONTENT OF OUR TESTS OR THE DIALECT
IN WHICH THEY ARE ADMINISTERED.....BUT OTHER
POSSIBILITY REMAINS..
A)MOTIVATIONAL FACTORS
CRITICS ARGUE THAT MANY MINORITY CHILDREN AND
ADOLESCENTS ARE NOT INCLINED TO DO THEIR BEST IN
FORMAL TESTING SITUATIONS.( MOORE, 1986:OGBU,
1994;STEELE,1997) THEY MAY BE WARY OF UNFAMILIAR
EXAMINERS (MOST OF WHOM ARE WHITE) OR STRANGE
TESTING PROCEDURES.
MORE OFTEN APPEAR TO ANSWER QUICKLY RATHER THAN
CORRECTLY TO GET THE UNPLEASANT TESTING EXPERIENCE
OVER WITH
CHANGES IN TESTING PROCEDURES TO MAKE THEM FEEL
COMFORTABLE CAN MAKE A BIG DIFFERENCE.

4. B) IMPACTS OF NEGATIVE STEREOTYPES
JOHN OGBU (1994)BELIEVES THAT NEGATIVE
STEREOTYPES ABOUT THEIR INTELLECTUAL ABILITIES
MAY CAUSE SOME MINORITY YOUNGSTERS TO FEEL
THAT THEIR LIFE OUTCOMES WILL BE RESTRICTED BY
PREJUDICE AND DISCRIMINATION, THEREFORE THEY
MAY REJECT CERTAN BEHAVIOURS SANCTIONED BY THE
MAJORITY CULTURE. THIS IS CALLED ‘STEREOTYPE
THREAT’
2.THE GENETIC HYPOTHESIS
RICHARD HERNSTEIN AND CHARLES MURRAY IN THE
BELL CURVE, IN 1994 ARGUED THAT ETHNIC
DIFFERENCES IN AVERAGE IQ SCORES WERE LARGELY
THE RESULT OF GENETIC DIFFERENCES AMONG
ETHNICITIES OR IN OTHER WORDS....IT IS THE NOTION
THAT GROUP DIFFERENCES IN IQ ARE HEREDITARY.
ARTHUR JENSEN (1985, 1998) AGREES WITH THIS
GENETIC HYPOTHESIS. HE CLAIMS THAT THERE ARE 2
BROAD CLASSES OF INTELLECTUAL ABILITIES WHICH ARE
EQUALLY HERITABLE AMONG DIFFERENT ETHNIC
GROUPS.

5. LEVEL I ABILITITIES
- INCLUDE ATTENTIONAL PROCESSES, SHORT TERM
MEMORY AND ASSOCIATIVE SKILLS
LEVEL II ABILITIES
- ALLOW ONE TO REASON ABSTRACTLY AND TO
MANIPULATE WORDS AND SYMBOLS TO FORM
CONCEPTS AND SOLVE PROBLEMS. ACCORDING TO
JENSEN, THEY ARE CORRELATED WITH SCHOOL
ACHIEVEMENT
HE FINDS THAT LEVEL I TASKS ARE PERFORMED EQUALLY
WELL BY CHILDREN FROM ALL ETHNIC GROUPS AND SOCIAL
CLASSES. HOWEVER , MIDDLE CLASS AND WHITE CHILDREN
OUTPERFORM LOWER0INCOME AND AFRICAN –AMERICAN
CHILDREN ON THE MORE ADVANCED LEVEL II TASKS.SINCE
LEVEL I AND II TASKS ARE EQUALLY HERITABLE WITHIN EACH
SOCIAL AND ETHNIC GROUPS, JENSEN PROPOSES THAT IQ
DIFFERENCES BETWEEN GROUPS MUST BE HEREDITARY
CTITICISM OF THE GENETIC HYPOTHESIS
- CORN SEEDS ANALOGY BY RICHARD LEWONTIN
(1976)
- DATA AVAILABLE ON MIXED-ETHNICITY CHILDREN
ALSO FAIL TO SUPPORT GENETIC HYPOTHESIS

6. 3. THE ENVIRONMENTAL HYPOTHESIS
- THAT PEOPLE AND MEMBERS OF VARIOUS
MINORITY GROUPS TEND TO GROW UP IN
ENVIRONMENTS THAT ARE MUCH LESS CONDUCIVE
TO INTELLECTUAL DEVELOPMENT THAN THOSE
EXPERIENCED BY MOST WHITES AND OTHER
MEMBERS OF THE MIDDLE CLASS
-a family’s poverty status and lack of adequate
income may mean that many children from low-
income families are undernourished which may
inhibit brain growth and make the listless and
inattentive ( Pollit, 1994)
-economic hardship creates psychological distress
A strong dissatisfaction with life’s condition that
makes lower-income adults edgy and irritable and
reduces their capacity to be sensitive, supportive and
highly involved in their children’s learning activities
- Low-income parents are often poorly educated and
may have neither the money nor knowledge to
provide their children with books, toys or other
experiences to an intellectually stimulating home
environment

7. SCORES ON THE HOME INVENTORY ARE CONSISTENTLY
LOWER IN LOW-INCOME THAN IN MIDDLE-CLASS HOMES (
BRADLEY, 1989; DUNCAN & BROOKS-GUNN, 2000) AND
CHILDREN WHO HAVE ALWAYS LIVED IN POVERTY AND
WHOSE PARENTS HAVE THE FEWEST FINANCIAL RESOURCES
ARE THE ONE WHO EXPERIENCE THE LEAST STIMULATING
HOME ENVIRONMENTS
YET, WHEN PARENTS PROVIDE MORE STIMULATING HOME
ENVIRONMENT, THEIR CHILDREN PERFORM MUCH BETTER
ON IQ TESTS
CAREFULLY CONDUCTED CROSS-ETHNIC ADOPTION STUDY
ALSO LEAD TO SIMILAR CONCLUSION