Ten years ago, I wrote with Atam Vetta a paper on 'Demographic behavior and behavior genetics', which showed clearly that Fisher's assumptions and heritability analysis are based on false assumptions (see the joint attachment). However behavior genetics had been increasingly used by a number of social scientists in psychology, in demography, in gerontology, in medicine, in biometry, etc. More recently, after sequencing the human genome, a number of scientists believed it would be possible to draw up a list of behavioral traits linked to each gene. Such a belief again was not verified., but this did not prevent behavior geneticists to argue that the links between genes and behavioral phenotypes will permit new advances in the understanding of human behavior.
There are in fact two questions to be answered: (1) Is human behavior influenced by genes? (2) If, yes, what is the 'magnitude' of this influence? The answer to the first question is evidently 'yes', and it can be said pointless. For the second question we can refer to Gilbert Gottlieb in a paper on 'Genetics and development' (2001): 'It is now known that both genes and environment are involved in all traits and that it is not possible to specify their respective weighting or quantitative influence on any trait'. He adds: 'this had been a hard-won scientific insight that had not yet percolated to the mass of humanity'.
This Nature-Nurture question is always under debate, and I think it may be of interest for many ResearchGate members to discuss it.
It is largely because scientists, be they natural or social, believe that genes are the determinants of the phsiology and psychology of the organism. In reality, while there are some gene products (i.e proteins) that can influence behaviour (like hormones), there are no genes that determine behavioural traits. However, most scientists would retort by saying that innate behaviour must be inherited biochemically by genes.
Yes, I entirely agree with you that the scientist’s interest on behaviour genetics lies in the fact that they believe genes are the determinants of the physiology and the psychology of organisms. But I think that the roots of the interest on behavioural genetics may be different to the roots for eugenics which is called nowadays ‘hereditarianism’.
I am, with other researchers, writing a paper on the four Baconian idols in order to see if they are still alive.
I found that the idols of the tribe correspond perfectly to behaviour genetics. Bacon said about them: ‘The human understanding is of its own nature prone to suppose the existence of more order and regularity in the world that it finds’. He gave the example of astrology for his time. I think that nowadays behaviour genetics play an equivalent role as you clearly showed it.
However the idols of the market place seem to correspond to eugenics and ‘hereditarianism’. Bacon said about them that they are ‘formed by the intercourse and association of men with each other’. Their political purpose is clear in order ‘to improve the inborn qualities of race’. They promoted the use of sterilization laws before the Second World War, and after it they assist the race towards the elimination of the unfit. They used the concept of heritability drawn from behaviour genetics to reach their political goals.
Joseph Hannon Bozorgmehr ·
you have said that there are no genes that determine behavioural traits. Do you believe that humans are born with blank slates? You might find Steve Pinker`s book on blank slates interesting
There is a myth that thinking is a gift instead of a skill. As long that this myth of thinking is a gift will be alive then the myth of behavior genetic will be alive.
Dear Ranjit Kumar Mal,
There are two theses in Steven Pinker book: The blank slate.
The first one is that human behaviour is influenced by genes. As I said in the presentation of my question, the answer to this thesis is of course yes and it can be said pointless. All individual’s observable traits are related to his or her physical characteristics, which are themselves genetically determined. Consider the example of skin colour. This trait is directly linked to genes. In a country like France where employment is a major problem, finding work is harder for someone with black skin. So that the fact of being unemployed is ‘influenced’ by the individual’s genetic endowment. The same is true for all characteristics of whatever kind. Even religious convictions and political opinions are behaviours subject to these genetic influences, through the action of processes of varying complexity.
The second one is that Steven Pinker uses behaviour genetics to measure the ‘magnitude’ of this influence. The reference to a ‘magnitude’ implies an acceptance that a measurement can be defined and calculated to assess the respective shares of nature and nurture, of genes and environment, in determining the trait in question. Yet introducing this concept of shares amounts to adopting an additive model in which the respective roles of genes and environment are played out independently of each other. Such a thesis has no scientific content as these factors operate in relation to each other. What occurs between them is not addition but interaction, and this interaction is the problem to be studied. Of course it is possible to take multiple measurements, feed them into a computer and obtain a figure for the ‘heritability’ of the trait. But what is the value of this wealth of calculations if we are unable to give any meaning to the results? The one-dimensional approach of the psychologist Pinker is a betrayal of the multi-dimensional reality of genetic influence.
Finally I entirely agree with Louis Brassard view that as long that the myth of thinking is a gift will be alive then the myth of behaviour genetic will also be alive.
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