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Ch. 3 - Genes, development and instinct

Posted: Sun Mar 18, 2012 8:54 pm
by Chris OConnor
Ch. 3 - Genes, development and instinct

Re: Ch. 3 - Genes, development and instinct

Posted: Wed Apr 04, 2012 9:45 pm
by Dexter
I feel like some of the arguments in evolutionary psychology are either reacting to strawman arguments or at least uninteresting ones. It talks about instinct and is arguing that environment is important as well as genetics. It mentions imprinting, where there is some learning involved with baby chicks in recognizing their mother and that it can go wrong. Therefore we can't say that it's purely genetic. But this seems pretty obvious.

Similarly it mentions taking the genes' eye view is not enough because there are environmental effects. But is anyone really suggesting otherwise?

Re: Ch. 3 - Genes, development and instinct

Posted: Fri Apr 06, 2012 8:27 am
by LevV
While both genes and environment are involved in development, it is the interaction between the two that I find so interesting. As the authors state:
“While it is true that most people take the interactionist view on board and are careful to emphasize the importance of both genes and environment, it is also true that many sometimes fail to appreciate the full implications of this standpoint”.

The authors give the example of the tendency of the media to simplify this complex process with reports on the discovery of the gene for athletic ability or sexual orientation.
It is clear that evolutionary psychology is showing us how complex the interaction of genes and environment really is. Their description of recent developments in the area of ‘instincts’ alone makes this book a worthwhile study. What were once thought to be fully formed inherited traits are now shown to include a learning component that begins well before birth!

Re: Ch. 3 - Genes, development and instinct

Posted: Fri Apr 06, 2012 9:12 am
by Dexter
LevV wrote:
The authors give the example of the tendency of the media to simplify this complex process with reports on the discovery of the gene for athletic ability or sexual orientation.
It is clear that evolutionary psychology is showing us how complex the interaction of genes and environment really is. Their description of recent developments in the area of ‘instincts’ alone makes this book a worthwhile study. What were once thought to be fully formed inherited traits are now shown to include a learning component that begins well before birth!
That's true. But take sexual orientation -- I'm not that familiar with the empirical evidence on heritability, I did a quick Google search. I believe that in twin studies it shows that you don't have a 100% correlation. But to me, I still think of it as a genetic predisposition and I think of it as having a "genetic cause" even though the environment might affect whether those genes are expressed. I don't know if the author would say that's the wrong way to think about it.

Re: Ch. 3 - Genes, development and instinct

Posted: Fri Apr 06, 2012 10:40 am
by LevV
I don’t think that the authors would disagree with your point that a particular gene may play a role in a predisposition toward a particular sexual orientation or any other trait for that matter. But look at what they say about the rest of the story:

"In most cases, traits are determined by a complex genetic cascade that involves a large number of genes as well as some aspects of the environment in which they develop, such as the order in which they are switched on and off. A gene may be involved in a particular trait not because it determines the trait but because it produces a particular effect that is crucial to the correct development of the trait."

In this paragraph, there are a few points that are left unclear. It may be because they wanted to keep this introductory book fairly short. For example, what exactly is the meaning of, “such as the order in which they are switched on and off”.

It looks like I’ll have to do a fair bit of additional research to fully appreciate this area of research into the human species.

My apologies for not including page numbers with my quotes. I'm reading this book on the program Kindle for PC (for the first time) and there is no indication of page numbers that would match the hard copy of the book.

Re: Ch. 3 - Genes, development and instinct

Posted: Mon Apr 23, 2012 2:44 pm
by lindad_amato
So far the book seems to be an argument that nature and nurture work together to assist in the development of the human. I never thought that it could be one or the other so it is interesting for me to see someone present this.

Re: Ch. 3 - Genes, development and instinct

Posted: Mon Apr 23, 2012 9:14 pm
by Dexter
lindad_amato wrote:So far the book seems to be an argument that nature and nurture work together to assist in the development of the human. I never thought that it could be one or the other so it is interesting for me to see someone present this.
The arguments often do seem like common sense, although I suppose there have been people arguing for one of the extreme positions

Re: Ch. 3 - Genes, development and instinct

Posted: Wed Apr 25, 2012 7:10 am
by LevV
Yes. With all the research that has been done in this area it seems pretty safe to say that genes and environment are more or less, equally important in determining the behaviour of humans. The authors are in agreement with this and then introduce us to some of the, “full implications of this standpoint”.

One outcome of the extension of this integrationist view they introduce us to is the development of the niche construction theory. This theory argues that a culturally learned behaviour can feed back on itself and have an effect on genes by acting as a source of selection. This theory is described more fully in chapter 2.
This theory is interesting to me because much of what I’ve read in this area suggests that human evolution came to a stop 50,000 years ago when homo sapiens emerged from Africa. Niche construction theory, on the other hand, suggests that humans play a more active role in the construction of their environment than was previously thought. I would like to see more of the evidence that supports this theory. It sounds like a very interesting area of research.