With reference to relevant research studies, to what extent does genetic inheritance
influence human behaviour
This essay will attempt to consider the extent to which genetic inheritance can
influence the human behaviour of intelligence. According to the third principle of the
BLoA, human behaviour is innate because it is to some extent genetically based. In
other words, genetic inheritance should be seen as inheritance of a genetic
predisposition towards the onset or development of a specific behaviour. An individual
can have a genetic predisposition towards a certain behaviour but without the
appropriate environmental stimuli, the behaviour will not manifest. This is known as
the diathesis stress model. Genes are segments of DNA inherited by the offspring
from the parents and can be considered responsible for the development of
behavioural characteristics. Behavioural genetics is the understanding of how genetics
and the environment contribute to the individual variations in behaviour, where the
premise is that the inheritance of DNA will influence behaviour. A single gene is not
responsible for a single behaviour but can be seen as a building block. Genetics alone
do not affect behaviour, other factors such as the environment will also influence the
development of an organism.
There are different types of studies which can be used within genetic research, these
include twin studies, adoption studies and family studies. Twin studies study the
correlation between genetic inheritance and behaviour due to the common genetics
shard by the twins. Monozygotic twins (MZT) share 100% genetic material, Dizygotic
twins (DZT) are fraternal and share 50% genetic material, which is the same as
between normal siblings. Twin studies usually compare sets of twins that are apart
with those that are together to make a correlation of their behaviour, this is done by
studying the concordance rate between them. Concordance rate can be defined as
the probability that a pair of individuals will both have a certain characteristic given
that one of the pair has the characteristic. Adoption studies allow researchers to study
the comparison between genetic and environmental influence on behaviour. Adoptive
children share no genes with adoptive parents but 50% of genes with biological
parents. This type of study helps us to consider the extent to which the environment
can play a role within behaviour and the extent of the role which genetic holds Family
studies study behaviour between family members who have similar genetics to
different degrees.
Intelligence is an aspect of behaviour which has been largely studied in relation to
genetics It has been questioned if intelligence is attributed to genetic or
environmental factors. As intelligence is difficult to measure and define, IQ tests
developed by Binet are used in much psychological research as a way to measure
intelligence.
A study which utilizes the use of twins in the Minnesota Twin Study conducted by
Bouchard et al. This was a longitudinal study involving over 100 self-selecting
identical twins, both MZ twins reared apart (MZA) and MZ twins reared together
(MZT), with the aim to determine how much of intelligence is attributed to genetics
and environment. Participants completed approximately 50 hours of medical and
psychological assessments including personality traits, occupational interests and
mental ability. The results showed that for IQ (measured by a standardized test called
WAIS), the concordance rates were 87% for the same person tested twice, 86% for
MZT twins, 76% for MZA twins, 55% for DZ twins reared together and 46% for
biological siblings raised together. Bouchard concluded that environmental factors do
play a role in the development of IQ but it is to a large extent inherited. In the sample,
70% of observed variation could be attributed to genetics and 30% attributed to other
influence human behaviour
This essay will attempt to consider the extent to which genetic inheritance can
influence the human behaviour of intelligence. According to the third principle of the
BLoA, human behaviour is innate because it is to some extent genetically based. In
other words, genetic inheritance should be seen as inheritance of a genetic
predisposition towards the onset or development of a specific behaviour. An individual
can have a genetic predisposition towards a certain behaviour but without the
appropriate environmental stimuli, the behaviour will not manifest. This is known as
the diathesis stress model. Genes are segments of DNA inherited by the offspring
from the parents and can be considered responsible for the development of
behavioural characteristics. Behavioural genetics is the understanding of how genetics
and the environment contribute to the individual variations in behaviour, where the
premise is that the inheritance of DNA will influence behaviour. A single gene is not
responsible for a single behaviour but can be seen as a building block. Genetics alone
do not affect behaviour, other factors such as the environment will also influence the
development of an organism.
There are different types of studies which can be used within genetic research, these
include twin studies, adoption studies and family studies. Twin studies study the
correlation between genetic inheritance and behaviour due to the common genetics
shard by the twins. Monozygotic twins (MZT) share 100% genetic material, Dizygotic
twins (DZT) are fraternal and share 50% genetic material, which is the same as
between normal siblings. Twin studies usually compare sets of twins that are apart
with those that are together to make a correlation of their behaviour, this is done by
studying the concordance rate between them. Concordance rate can be defined as
the probability that a pair of individuals will both have a certain characteristic given
that one of the pair has the characteristic. Adoption studies allow researchers to study
the comparison between genetic and environmental influence on behaviour. Adoptive
children share no genes with adoptive parents but 50% of genes with biological
parents. This type of study helps us to consider the extent to which the environment
can play a role within behaviour and the extent of the role which genetic holds Family
studies study behaviour between family members who have similar genetics to
different degrees.
Intelligence is an aspect of behaviour which has been largely studied in relation to
genetics It has been questioned if intelligence is attributed to genetic or
environmental factors. As intelligence is difficult to measure and define, IQ tests
developed by Binet are used in much psychological research as a way to measure
intelligence.
A study which utilizes the use of twins in the Minnesota Twin Study conducted by
Bouchard et al. This was a longitudinal study involving over 100 self-selecting
identical twins, both MZ twins reared apart (MZA) and MZ twins reared together
(MZT), with the aim to determine how much of intelligence is attributed to genetics
and environment. Participants completed approximately 50 hours of medical and
psychological assessments including personality traits, occupational interests and
mental ability. The results showed that for IQ (measured by a standardized test called
WAIS), the concordance rates were 87% for the same person tested twice, 86% for
MZT twins, 76% for MZA twins, 55% for DZ twins reared together and 46% for
biological siblings raised together. Bouchard concluded that environmental factors do
play a role in the development of IQ but it is to a large extent inherited. In the sample,
70% of observed variation could be attributed to genetics and 30% attributed to other
