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Genetics and behavior

Posted: Mon May 02, 2011 6:47 pm
by EddieG
I seek help regarding the issue of genetics, behavior, and free will.

Tell me, how would you respond to the claims made in these short commentaries? (Now, just so you know, this guy claims he works for a biotech company. Maybe he's biased? I don't know. He also claims that intellect and leadership abilities are innate and that it's a waste of time to even try basically.)

- http://freewill.typepad.com/genetics/20 ... nurtu.html (Nature vs. Nurture; The tale of the Elevator and the Thermostat)

Compares us to a thermostat or an elevator, which claims that we can change, but only within our limits: "I believe human behavior and variation is (nearly) 100% nature, and 0% nurture, because the only nurture we are capable of responding to must be part of our very design. Two elevators on different floors are not different. The differences in outcome are based on planned branching points in the design itself. They are the same - in the same way that a penny may land heads or tails yet still be the same penny!"


- http://freewill.typepad.com/genetics/20 ... m_wit.html (The problem with Heritability)

"If the variation in height between identical twins (who have identical genes) is 2 inches, this is 0% heritable, because it's not based on genetic differences (there are none). It must be explained by differences in their environment (food, disease, etc). Yet this idea breaks down, when the environment (nurture) is inherent (and anticipated) in the design of the organism (nature) itself, especially when the nurture acts as a trigger, for which the organism is designed to respond. Also, genes are like algorithms. They accept complex inputs, and can react with complex outputs over time, often using memory to delay their effect. (By "genes" here, I mean the entire set of interacting brain structures, nerves, hormones, transmitters that are built through the activity of proteins described by the genes.) A "gene" by this definition includes "detection" circuitry, so it knows when environmental triggers occur. Consider an imaginary "niche seeking" gene. Teenagers are always trying to find their own unique niche, to make them different from their friends. If two teens have the same "niche seeking" gene, they'll want to be unique from each other and avoid duplicating the other’s behavior. When one lifts his arm, the other (after observing this action) lifts his leg instead. When one goes outside, the other stays inside. When one rolls his eyes, the other one sneezes, just to be different. Same gene, different outcome.Although the ability to recognize abusive scenarios is shared in the twins (since how could a gene have any effect unless it recognizes the various scenarios for which it is designed to be affected?), only one individual received this environment. Yet both twins have the same innate branching circuitry. If situation A, then outcome B. If situation C, then outcome D. Just because the outcomes are different does not mean that the behavior isn't 100% genetic. The environmental scenario detection is built into the design of the genes (i.e. the brain circuitry designed by the genes)." [Note: I didn't include everything he said in the article, I skipped some things to focus on what's relevant]


- http://freewill.typepad.com/genetics/20 ... as_th.html (Everyone has the genes for every human trait, but an "on switch" for very few)

"It's important to understand that not all of our genes are put to use. A shy person may have their "outgoing genes" permanently switched off [My own emphasis here] by a few "master genes". Most of the 1% difference among humans can be found in the genes that act as master keys."

- http://freewill.typepad.com/genetics/20 ... tain_.html (We only retain or seek out experiences (nurture) which resonate with our genes (nature))

"We only retain or seek out experiences (nurture) which resonate with our genes (nature). Parents can try to force their daughters to play with fire trucks and baseball bats, but girls will usually reject them, and return to playing with the dolls they love. Most people deny this simple fact, until they have children and then sheepishly admit it.

The larger question still remains as to what invariants, fuzzy and inexact as they are, the inner eye can recognize in the environment, and what "trigger points" or "branching points" are set up in the inner eye to respond. The inner eye has little power except the recognition of vague landmarks in the environment (as a frog can recognize blurry dots in the sky and associate them with flies for its dinner)."

So, the third quote worries me the most. He's saying that some personality genes are permanently switched off, which, logically, would imply that some are permanently switched on.

The second thing that worries me is that according to him (especially the second point here, "The problem with Heritability"), we basically all act the same when the appropriate environmental input is given to the appropriate gene which in turn is permanently turned on or off by a master gene, etc. I am not including "thoughts" and your "own beliefs" as part of this because I'm using the environment to mean strictly that which you come into contact with. I know people use it differently, but I'm trying to make a point so as to highlight the role of personal responsibility, and personal choice above mere environmental inputs.

I think the only way out of this is by claiming that in the end, it's your own decision as to how you react to the environment. E.g. a child can refuse to obey his or her parents and thus, though "their genes" came into contact with the environmental input, their genes did or didn't express because of their refusal. There is some evidence that mental activity can affect gene expression, and it comes from epigenetics:
- http://articles.latimes.com/2010/may/03 ... e-20100503
- http://blog.webgenomeproject.org/epigen ... -you-free/#
- http://www.brainhealthhacks.com/2008/07 ... xpression/
- http://esciencenews.com/articles/2011/0 ... expression


My problem is, how can our thoughts control everything if some genes are "permanently switched on or off"? Do our thoughts also affect master genes?

However, there's something about this that doesn't make sense (to me, personally, that is). If our genes are so fixed in place, how are we supposed to adapt to our ever-changing environment? How does it make sense that "the only nurture we are capable of responding to must be part of our very design"? Well, in that case, aren't we in trouble from a survival point of view? It's this "master gene" thing that confuses me. So this guy admits that genes respond to environmental inputs, but only the ones that our master genes allow us to respond to?

What would make sense to me is that our conscious self can, through its own choices, direct which of the personality traits already in your genes becomes "active", and which don't activate due to gene expression.

My only problem is that this guy claims some master genes permanently switch on or off the genes responsible for behavior, which makes little sense considering how much the environment affects gene expression. Plus, there has to be at least some influence the mind has in controlling behavior.

Please add your input.

Thank you,

-Eddie

Re: Genetics and behavior

Posted: Sat May 21, 2011 9:59 am
by Tevko
This seems to be just another non testable theory passed around as "science." All because some guy who is rather great at story telling figured out how to compare human behavior to Gene expression. The only catch - Human behavior includes beliefs, so if I do not except the premise of those articles, do I have a belief gene switched off?

Thats why you cant test such a thing, because in the end whats to say your genes aren't leading you to accept a false premise?