There are a few people that have certain biases.
What really happened post exposes an antisemitic person who will never change as he has an ingrained hatred for some people.
Base intelligence is a factor of genetics as well as environmental conditions.
Other factors that can affect intelligence:
Social and environmental deprivation
All really fit nicely under environmental conditions.
As to race:
Race and culture
Many studies have noted racial and cultural differences in performance on lard intelligence tests (Jensen, 1969; Kennedy, 1966). Jensen (1969) observed clear differences in the cognitive competence of whites and blacks,studies conducted by Lesser, Fifer, and Clark (1965) investigated the verbal reasoning, number facility, and space conceptualization of children from : groups: Jewish, Chinese, Puerto Rican and black.
They found that racial membership significantly influenced both the pattern and level of intellectual sentence. In fact, racial differences were more prominent than the SES differences. Culture refers to a system of beliefs, attitudes, and values that assed from one generation to the next. In Indian context, there are prominent subcultures defined by caste groups, and traditional parental occupations.
The socialization practices in these subcultures are different. Studies have been conducted in rural Orissa comparing children of different groups.
The Harijan children scored west among the three groups and the Brahmins scored the highest. The Brahmins have a highly verbal articulate culture compared to the other groups; studies conducted in this region (Das and Singha, 1974; Jachuck and Mohanty, 1974) have reported significant differences in the cognitive level of children differing by caste, culture, and SES.
It may be unfair to compare the performance level of children from different cultures, as the skills required for successful adaptation in different cultures great deal The skills tapped by the standard cognitive tests are those that are demanded in more technologically advanced cultures and higher SES groups.
As a result the tests are biased in favor of their competence, and it is no wonder that we find inferior performance of lower caste children on these. The appropriateness of the test items has to be considered in any investigation comparing the performance of children from various cultural and groups.
Could the studies be included under environmental conditions?