Individual Differences

Running head: Individual 1
Individual Differences
by
Course:
Tutor:
University:
Department:
Date:

Individual 2
Abstract
James Flynn has studied the association between genes and environment and human intelligence
(HI) for over 40 years with particular inspiration from previous authors such as Arthur Jensen in
1977. Jensen’s found out that there was no environmental justification of the IQ variance
between African American and whites; an aspect that worried Flynn causing him to conduct
more studies on the same. Flynn later demonstrated through the “Flynn effect” that there had
been immense IQ gains. The Dickens and Flynn model later proved that the essence of IQ gains
could not be ignored as much as they were not g gains. Based on the current improvements, the
author offers in-depth insight into the contribution of genes and environment on HI.
Introduction
The influence of genes and the setting on HI has been an area of study by Flynn for over 40
years. The research was sparked by the findings of Arthur Jensen in 1977 on how the frailties of
the environment within cohorts proposed similarity in the weakness between groups. To Flynn,
this was an indication that there was no environmental justification of the IQ variance between
blacks and whites. Moreover, it meant that the impact of environment between cohorts could be
disregarded. It is such discrepancies from previous research that prompted Flynn to conduct
further in-depth studies on the relationship between genes and environment and HI. The author
cross-examined several authors in the field to come with a comprehensive view. The objective of
this essay is to examine the arguments of Flynn (Flynn, 2018) about the comparative input of
genes and the environment to HI for the past forty years.
Flynn’s opinions on the role of genes and environment to HI are as a result of 40 years of
research based on previous researchers with a particular emphasis on Arthur Jensen’s research.

Individual 3
Flynn’s arguments revolve around Jensen’s arithmetic, the Dickens/Flynn model, Lewontin and
arithmetic which results to the development of the sociological arithmetic as a solution to the
discrepancy that arises from the previous models. According to Jensen, genes and environment
plays a key role in explaining the black-white IQ gap. The author used identical twins; born and
brought out in a different environment, to prove his point. The author argued that if only the
setting caused the IQ variations, then the twins should develop with relatively similar IQ, and if
the genes were the single cause, they should develop with identical IQs. The outcomes of the
twin studies indicated that the environment was less significant than genes in determining human
intelligence. However, Flynn was not content with the conclusion of Jensen on the role of genes
and settings on HI. Thus, prompting him to use a social science model with his own life as an
example. He considered the environmental factor to be ‘the years of schooling’. According to the
findings of Flynn, genes did not render schooling as a weak factor within and between the cohort
group (the generation of Flynn and that of his father). In other words, the genes in the family of
Flynn accounted for much predictability with environment accounting for little.
The Dickens/Flynn model was designed to solve the problem of environment weaknesses within
a generation and environment. The model explains the value of genes within a cohort of same
age the idea of individual multiplier (IM) and social multiplier (SM) to explain the strength of
the setting. The authors used identical twins and found out that better genes place someone in a
better environment which further promotes one's performance or skill. An advantage of a good
gene at birth is that it is reproduced into a greater benefit in adulthood, hence called an IM. On
the other hand, an improved environment boosts performance or skill which further forces the
person to adjust to its level, and that develops even better quality of output, and thus becomes an
advantage to the individual, and such a setting improves one’s output, creating a much more