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Neurological Basis of Behavior (PSY - 610)

Lesson 12

GENES AND EXPERIENCE

Objective:

· To understand the Brain behaviour relationships from the perspectives of biological systems.

In this section of the module the students would go through and understand Biological systems- their

genetic basis and similarities with other animals. Mendelian Genetics. Where is the genetic

programming of behaviour (if any) Watson Crick Model. What are the similarities and differences

between species, progenies of higher order animals, including homosapien? How much do genes

contribute to behaviour: The discipline of Behavior genetics?

Behavioral Characteristics

In this lesson we will continue with the discussion on the genetic basis of higher order behaviours. In

the last lesson, we had discussed Schizophrenia which has strong genetic basis as shown by research.

Intelligence: Sir Francis Galton and Darwin were first cousins. Both started new ways of thinking. Sir

Francis Galton laid the basis of Statistics and Darwin gave us the theory of Evolution. Galton studied

the lineage of famous English men found genius is hereditary but we cannot rule out the possibility of

environmental influences ( upper class, royalty provided better breeding grounds for training children to

take on important assignments--like training a crown prince). Sir Julian Huxley (Biologist) Aldous

Huxley (writer), both grandsons of Thomas Henry Huxley and great grandson of Leonard Huxley. Thus

it appears genius runs in the family! John Noyes started a new thinking called Eugenics, where he

propagated that scientific breeding can produce brilliant offspring leading to perfectionism. He initiated

a complex system of community living of highly educated and well to do professionals. There were 58

children born in the community. They were healthy only 6/58 died compared to the mortality rate of 45.

The surviving children started corporations, hospitals which were bases of present day entrepreneurship

and businesses of the US.

The view that intelligence is inherited is controversial as there are several issues which come up-

how is intelligence defined or measured?

Intelligence is a sum total of many abilities. It is possible that these are inherited, but there is evidence

that environmental stimulation does make a difference (early stimulation?). It is well documented that

black children who performed poorly on IQ tests when coached on test taking showed an improvement

of scores of as much as 20 points. This coaching is more effective if children younger. Early

stimulation is important.

Environmental influences:

Environmental influences can affect intelligence, if the same individual is tested again after a period of

several years it is possible to gain about 20 points (Does this mean IQ increased?)

In Israel children have to live in the Kibbutz, separate from their parents. Children in Kibbutz coming

from European descent had I.Q. scores above 100 points, whereas children from Oriental/African

descent 80-90 points. However after 4-5 years their scores are similar.

Similarly, Monozygotic (MZ) twins reared together had a higher correlation on IQ scores(r=.92). This is

the same for height, weight, and school achievement. When MZ are reared separately the correlation of

IQ falls to .88 and school achievement falls to .66. In Dizygotic (DZ) and siblings the correlation falls

and in unrelated individuals the correlation of IQ falls to .25.

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Neurological Basis of Behavior (PSY - 610)

Critical thinking about intelligence testing

1. Is Intelligence influenced by culture?

2. Intelligence Tests?? Do they measure innate intellectual capacities or cultural learning?

Alcoholism: is another trait which evidence has shown to be genetically linked, especially that it is

transmitted from father to sons. Longitudinal studies have been carried out in Scandinavian countries

by Goodwin and colleagues (1979) as it is possible to follow children in foster homes through

records. It was reported that predisposition to alcoholism is 4 times higher in males. Research by

Schukit, Goodman and Winokur (1972) showed that alcoholism in half sisters or half brothers with

an alcoholic parent (living with them as well) was 46% (same if they did not live with alcoholic

parents). On the other hand, if foster parents were alcoholic the frequency is much lower about 15%.

There have been a large number of researches to identify the genetic basis of other behaviors. In one

study it was reported genetic predisposition to opiate addiction in rats. Rats were fond of morphine,

preferred it over water after tasting it for the first time!

We still have a lot of research to do before we can separate clearly the effects of environment or

environment and it is ongoing keeping in view the large number of variables.

References:

1. Kalat J.W (1998) Biological Psychology Brooks/ Cole Publishing

2. Carlson N.R.(2005) Foundations of Physiological Psychology Allyn and Bacon, Boston

3. Pinel, John P.J. (2003) Biopsychology (5th edition) Allyn and Bacon Singapore

4 Bloom F, Nelson and Lazerson (2001), Behavioral Neuroscience: Brain, Mind and Behaviors (3rd

edition) Worth Publishers New York

6. Bridgeman,B (1988)The Biology of Behaviour and Mind. John Wiley and Sons New York

7. Brown, T.S and Wallace P.S. (1980) Physiological Psychology. Academic Press New York