Genes and Behaviors: does one cause the other?

I only ask because I've been in an on-going 'debate' on another forum with a person who genuinely believes that genes are the direct cause of given behaviors, specifically the behavior of addiction. I find this conclusion of my opponent to be incredible because just in my own life there's my sister, mother, and myself whom all are strongly related to family lines where addiction to alcoholism is ever present. Now, take me and my sister in particular, she can't stop drinking or taking other drugs, but me I stop anytime I want.

Now, take that and the current discoveries related to pseudo-genes where it seems the expression of genetic 'traits' greatly depends on its sister pseudo-gene. This gene/pseudo-gene relationship suggests a non-reductionist model of the 'behavior' of genes themselves (and their expression) more so than the traditionally assumed view of the 1-to-1 reductionist view/model.

So, as the question is posed in the thread name: do genes cause behaviors?

Post 1

Sunday, August 3, 2008 - 7:17am

You may have a related gene on that, but you might yourself have a recessive too, which in your case mitigates the tendency......

Technically, if you posit this as a continuum in biological complexity, you have to admit the genes then cause behaviors in the lower animals - so why not yours, in at least some cases be of an autonomic nature...
(Edited by robert malcom on 8/03, 7:21am)

Post 2

Sunday, August 3, 2008 - 8:22am

I've not really had 1 to 1 experience with a person who has addiction problems.

The best indication we have is "identical twin" studies, where two people start their lives with the same genes, and then through their lives we compare the two to see how their life of learning and experiencing different things changes how they behave.

I'm pretty confident that there are genes that make people more highly susceptible to destructive addiction. A person with a strong combination of these genes is still capable of deciding not to drink (or whatever) too much, but its a lot harder for them to come to such a conclusion.

But why do they decide to do something too much? A combination of genetics and learned behaviors and feelings and reasoning... all having different weights and different qualities for each person.

Best wishes for you working through this Bridget.

Post 3

Sunday, August 3, 2008 - 9:10am

I have heard that the twins study is shot through with problems - but I don't have any first hand information on that.

Clearly genes create the phenotype who does the behavior. And with organisms with less awareness, say a fruit fly, it is possible, I am told, to breed for a behavior. There are even behaviors more characteristic for, say, a pit bull as compared to an Irish Setter, and they appear to breed true.

But, with each level of complexity of consciousness there is an increase in the need for learned behavior and that introduces an added level of 'agency' - it is possible to use training to make a very docile or timid pit bull and an agressive Irish Setter - to override the tendency that would have arisen from genes.

With people, you have the longest and most intensive need for learning and then add to that our ability to exercise volition. Two forms of 'agency' that can overide or influence any tendencies that genes might have.

With substance abuse there is an added complication. Our form of awareness lends itself to psychological problems. We can form defensive habits to protect against anxieties that arise from ways of using our consciousness that we picked up in our early years from our family. This makes it tough to determine if a high number of users in a family line have learned issues that lend themselves to self-medication or if there is a gene that increases the physical dependency component of potentially addictive substances, or both.

Because choice is in the arena - determinism is the one thing that can be ruled out. If we don't rule out genes as the sole agent of human behavior, then we have to explain how genes encode for all of these things that we would have to refer to as psuedo-choices in the face of our complex interactions with society, art, science, culture, ideas, etc. - Just can't be done.

My belief is that each new layer of 'agency' that forms (and itself is initially a product of genetic evolution on one level and becomes an evolutionary mechanism of its own) is more agile than genetic evolution and takes what the phenotype has been given by genetics and influences from there. We have this conceptual ability which gives rise to a culture with ideas and the capacity to react to ideas almost automatically or critically (we choose). So, that adds an additional layer of 'agency' which is the meme systems we are exposed to and our concious practices in reaction to it - for those who don't make a practice of thinking for themselves, they are being driven by genes, by learning, by memes, and psychological habits. Since we have volition, we exercise what choice we have within that complex arena.

I realize I'm abusing the word 'agency' in my usage, but it helps to see that there is a competition going on as to which 'agent' is effective in steering us: genetics, learning, memes, psychological habits, and/or volition. There is of course overlap and reciprocal cause and effect relationships between some of the 'agents.' Lots of voices offering to back-seat drive.

We never escape being a creature with all these different aspects - just as we will always have both reason and emotion, body and a mind, be individuals in a society, work from what we have learned yet able to think for ourselves, rational and irrational.

Post 4

Sunday, August 3, 2008 - 3:32pm

My short answer, which is admittedly glib and wily, is that it depends on how tight they are -- and whether they're on the Double-Mint Twins. Tight jeans on those twins always makes me google (an instance of jeans causing behavior).

:-)

That being said, there's scientific evidence both ways -- scratch that -- there's 3-way evidence on this. There's evidence that genes cause behavioral tendencies, there's evidence that environment causes behavioral tendencies, and there's evidence that individuals -- "agents" -- take part in causing either their own environments, or their own unique style of reaction to otherwise-common environmental factors (making strict "environmental causation" conceptually-suspect).

Here's evidence that genes cause behavioral tendencies:

Hum Genet. 2007 Mar;121(1):125-36.

Contributions of the DAT1 and DRD2 genes to serious and violent delinquency among adolescents and young adults.

Guo G, Roettger ME, Shih JC.

Department of Sociology, University of North Carolina, Chapel Hill, NC 27599-3210, USA. guang_guo@unc.edu

As far as we know, this is the first national study that reports compelling evidence for the main effects of genetic variants on serious and violent delinquency among adolescents and young adults. This study investigated the association between the self-reported serious and violent delinquency and the TaqI polymorphism in the DRD2 gene and the 40-bp VNTR in the DAT1 gene. The study was based on a cohort of more than 2,500 adolescents and young adults in the National Longitudinal Study of Adolescent Health in the United States.

The trajectories of serious delinquency for the DAT1*10R/10R and DAT1*10R/9R genotypes are about twice as high as that for the DAT1*9R/9R genotype (LR test, P = 0.018, 2 df). For DRD2, the trajectory of serious delinquency for the heterozygotes (A1/A2) is about 20% higher than the A2/A2 genotype and about twice as high as the A1/A1 genotype, a phenomenon sometimes described as heterosis (LR test, P = 0.005, 2 df).

The findings on violent delinquency closely resemble those on serious delinquency. The trajectories of violent delinquency for the DAT1*10R/9R and DAT1*10R/10R genotype are again about twice as high as that for DAT1*9R/9R (LR test, P = 0.021, 2 df). The two homozygotes of DRD2*A1/A1 and DRD2*A2/A2 scored lower (LR test, P = 0.0016, 2 df) than the heterozygotes.

The findings in the models that consider DAT1 and DRD2 jointly (serious delinquency P = 0.0016, 4 df; violent delinquency P = 0.0006, 4 df) are essentially the same as those in the single-gene models, suggesting the absence of a significant correlation between the two genetic variants. These results only apply to males. Neither variant is associated with delinquency among females.

==========

Recap:

Genes matter (for males, at least). Females aren't genetically pre-determined to have the same behavioral tendencies in all of the same ways that men are -- though they may be genetically pre-determined to have their own kind of behavioral tendencies.

Here's evidence that environment causes behavioral tendencies:

Arch Pediatr Adolesc Med. 2008 Feb;162(2):145-50.

Being bullied as an environmentally mediated contributing factor to children's internalizing problems: a study of twins discordant for victimization.

Arseneault L, Milne BJ, Taylor A, Adams F, Delgado K, Caspi A, Moffitt TE.

Medical Research Council Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Campus Box P080, De Crespigny Park, London SE5 8AF, England. l.arseneault@iop.kcl.ac.uk

OBJECTIVE: To test whether the experience of being bullied has an environmentally mediated effect on internalizing symptoms in young children.

DESIGN: A genetically informative, longitudinal 1994-1995 birth cohort.

SETTING: A nationally representative sample from the United Kingdom.

PARTICIPANTS: We examined 1116 twin pairs who are participants in the Environmental Risk Longitudinal Twin Study. Main Exposure The experience of being bullied between the ages of 7 and 9 years.

MAIN OUTCOME MEASURES: Mothers' and teachers' reports of children's internalizing problems at 7 and 10 years of age.

RESULTS: Monozygotic twins who had been bullied had more internalizing symptoms (mean, 0.23; SD, 1.00) compared with their co-twin who had not been bullied (mean, -0.13; SD, 0.86), indicating that being bullied has an environmentally mediated effect on children's internalizing problems (beta, 0.36 [95% confidence interval (CI), 0.18-0.54]). This effect remained significant after controlling for preexisting internalizing problems (beta, 0.26 [95% CI, 0.09-0.44]).

CONCLUSIONS: Being bullied at a young age is an environmentally mediated contributing factor to children's internalizing problems. Intervention programs aimed at reducing bullying behavior in schools and in the community have the potential to influence children's early symptoms of mental health problems.
=========
Recap:
Environment matters.

And here's evidence that individuals -- "agents" -- take part in causing either their own environments, or their own unique style of reaction to otherwise-common environmental factors (making strict "environmental causation" conceptually-suspect):

Psychol Med. 2007 May;37(5):615-26.

Genetic influences on measures of the environment: a systematic review.

Kendler KS, Baker JH.

Virginia Institute for Psychiatric and Behavioral Genetics, Department of Psychiatry, Medical College of Virginia of Virginia Commonwealth University, Richmond, VA 23298-0126, USA. Kendler@vcu.edu

BACKGROUND: Traditional models of psychiatric epidemiology often assume that the relationship between individuals and their environment is unidirectional, from environment to person. Accumulating evidence from developmental and genetic studies has made this perspective increasingly untenable.

METHOD: Literature search using Medline, PsycINFO, article references and contact with experts to identify all papers examining the heritability of measures of environments of relevance to psychiatry/psychology.

RESULTS: We identified 55 independent studies organized into seven categories: general and specific stressful life events (SLEs), parenting as reported by child, parenting reported by parent, family environment, social support, peer interactions, and marital quality. Thirty-five environmental measures in these categories were examined by at least two studies and produced weighted heritability estimates ranging from 7% to 39%, with most falling between 15% and 35%. The weighted heritability for all environmental measures in all studies was 27%. The weighted heritability for environmental measures by rating method was: self-report 29%, informant report 26%, and direct rater or videotape observation (typically examining 10 min of behavior) 14%.

CONCLUSION: Genetic influences on measures of the environment are pervasive in extent and modest to moderate in impact. These findings largely reflect 'actual behavior' rather than 'only perceptions'. Etiologic models for psychiatric illness need to account for the non-trivial influences of genetic factors on environmental experiences.

=========

Recap:

Individuals matter.

Ed

(Edited by Ed Thompson on 8/03, 3:38pm)

Post 5

Sunday, August 3, 2008 - 5:36pm

A gene is a length of DNA which either codes directly for a protein, or which affects whether or not another coding gene will be expressed. For example, a cell might have a gene that codes for a protein that metabolizes a type of fat. When levels of that fat drop and its metabolites build up, a regulator gene will respond to their presence by inhibiting expression of the gene that produces the metabolizing protein.

Genes code either directly for proteins, or they regulate other protein producing genes. Proteins are not behaviors.

How does a gene affect behavior? Nerve cells have receptor proteins on their surfaces which react to the presence of neurotransmitters, drugs, and other chemicals in the blood. The number and efficiency of these receptors depends on the version of the protein coding and regulatory genes that produce them. If I have a gene that causes me to produce twice as many receptors for adrenaline or receptors that are twice as sensitive then I will respond more strongly to a low level of adrenaline than someone who does not have that gene. Other genetically determined factors will come into play. My brain may respond to oversensitive adrenaline receptors by producing an inhibitory substance. The amount and efficiency of this substance will also differ genetically. Some substances, like testosterone, have a cascading effect, a positive feedback that causes drastic on-off effects like the masculinization of an embryo. The expression of other traits can be governed by dozens or even hundreds of genes, each with its own number of copies and different "versions" and effects. In fact, it is very difficult to treat the expression of traits reductively. A trait such as "blindness" can be caused by hundreds of mechanisms, from the lack of development of eyes at all, to problems with eye tissues or brain structure, all the way down to diabetic or blindness or glaucoma which are caused by metabolic defects that have nothing to do directly with the eye itself. Genes for such things as sexuality are hardly ever so straight forward. If you have a gene for attraction to the scent of males, and a gene for ovaries, you are a possibly a heterosexual woman. The same gene for male attraction along with the gene for masculinization results in a possible male homosexual. Is the gene for heterosexuality or homosexuality or just for sexuality?

One's biochemical nature is the complex product of one's genes as expressed in the environment. Each gene is part of the environment of another. Yet the organism is emergent. Born with a sweet tooth, we can chose to take saccharine. A pistol built to spec can be just as good a paperweight as murder weapon. That you body reacts to a certain chemical in a certain way may be a biological given. What you do with that given may transcend biology. Nature's reasons are her own; we can choose happiness.

(Edited by Ted Keer on 8/03, 6:46pm)

Post 6

Tuesday, August 5, 2008 - 3:16pm

Steve,

Well spoken, clear post.

Based upon available evidence - however incomplete, given the difficulty of gathering data - I agree that there are a number of factors which ultimately determine an individual's behavior. It would be foolish to exclude genes or environment. Your comments on other 'agencies' adds logical further clarification of the complexities involved.

jt

Post 7

Tuesday, August 5, 2008 - 3:18pm

Ted,

Valid point.

jt

Post 8

Tuesday, August 5, 2008 - 11:09pm

I've sanctioned Ted's post for the clarity and for this paragraph in particular: "One's biochemical nature is the complex product of one's genes as expressed in the environment. Each gene is part of the environment of another. Yet the organism is emergent. Born with a sweet tooth, we can chose to take saccharine. A pistol built to spec can be just as good a paperweight as murder weapon. That you body reacts to a certain chemical in a certain way may be a biological given. What you do with that given may transcend biology. Nature's reasons are her own; we can choose happiness."

There are two other complexities in the world of genes that fascinate me. One is embryology through development where the genes act as a blueprint of the final product plus a set of instructions detailing what to do at each stage of the organism prior to birth, hatching or germination (in the case of plants) and the development after that to become the adult - as opposed to the role of genes in our day to day existence. Day to day gene operation is like a manual explaining about keeping the various consumables in supply and making extras when there is damage, so as to make repairs.

Always genes are just producing a protein - either as end product or to catalyze other reactions, - drawing on the complexity of the 3-d folding of the protein to create specific shapes and electrochemical attractions. But what complexity there is just in the regulation of that symphony of day to day production! We have about 3.24 x 10^22 Hemoglobin subunits in an adult body (4 to create a single hemoglobin molecule) and their half-life is about 50 days. (Each of those proteins is made up of about 4,000 atoms.) So every day the genes in cells that produce Hemoglobin make those four protein subunits in quantities of exceeding 6.48 x 10^20 per day!

And then add to that the complexity of regulating for the stages of embryology and later development.

Aristotle was the first to come up with the theory of Epigenesis: that organisms went through a series of gradual steps through the course of developing from, say a fertilized egg into a newly born infant. Prior to Aristotle everyone held that a baby was in the womb in some miniature form of an already developed human and just grew till time for birth. Embryology is the study of the development of an embryo. Ted said, "One's biochemical nature is the complex product of one's genes as expressed in the environment." And he pointed out that each gene is part of the environment of the others. And the rest of the environment in the beginning is the womb. The sperm and the egg joining starts a complex morphing from a single cell, now with a full complement of DNA (half from Mom, half from Dad). This capacity of germ cells to split and then to join with their other half is also a genetically evolved trait - evolution invented sex. The solo dance that follows as cell divides and with divisions begins to differentiate. We see signs of our ancestors in some of the early stages. You can think of as a design for a transformer toy that has elaborate mechanisms that cause it to unfold and erect itself when its box is opened. Now imagine that the designer wants to have the final shape different but he doesn't want to redesign from scratch. He located the area in the chip with a program for unfolding, say a tail, and modifies it so the tail forms, but during the unfolding of the tail, it then changes into a.... backpack. Evolution, as the designer, has taken this initial design for the simplest of all DNA structures, whatever that was, and step by step has introduced changes that cause us to unfold differently than our ancestors - and some of that initial unfolding is still visible. Just as a computer program has to be a sum of its instructions executed in some sequence over time, ignoring the fact that some instructions may never be executed, our genome is a set of instructions for unfolding into a new-born from a fertilized egg. Then each cell has it's own portion of instructions to carry on with the postpartum development, and instructions on when to stop growing. Certain cells have instructions to bring about changes that become adolescence. So, in this we see genes as complex set of instructions for building an adult, by starting with sperm and egg. Sperm has to swim. The DNA from the fertilized egg unfolds in way that takes us through the stages that form every single organ system - every cell that will be in the new born and do it in away that shows traces of the parts we no longer have (like gills, tails, etc.) All of this takes place in the environment of the womb. Then the functioning infant's cells have DNA instructing in the growth and the instructions differ from tissue to tissue, because the environment for DNA starts with the interior organelles of the cell it is in. The instructions carry through to adolescence to get to the adult.

It is extraordinary enough that our DNA is there like a template, that reacts to changes in the body to regulate production of needed proteins - for maintaining a balance of some protein used up in some normal process of being or of aging, or sudden demands to trauma or loss to make repairs. But that it also has within that coding all that is needed to create the germ-line cells that will have all the coding needed to do all of the development needed to create another adult... well, its just mind-blowing!

The other complexity is the concept of the Extended Phenotype. Which refers to any role of genes in the developing of some portion of the environment outside of the individual. It would be said to have been created as a result of a genes (like the beaver's dam, or a spider's web) and to be a variation in the environment that effects the success of the gene carrier in leaving offspring.

The Extended Phenotype is about the variations outside of the individual (the pheontype) that are a result of the evolutionary interaction of the individual's genes with these external variations. An example: One genome in the beaver family codes for a beaver that consistently builds bigger dams. If that proves to be successful, maybe because the larger resulting pond provides greater safety from predators, then those genes will be selected for. A case where the dam is from the genes and evolution is acting on the dam.

At one level, our culture, our science, our technology are all products of the genes that produced the fore brain that gave rise to the ability to function cognitively as we do. Variations in these examples of extended phenotypes that are selective for breeding will be recreated in ever greater number if they are a genetic expression. But that is where it gets really tricky. Our extended phenotype is capable of sustaining an evolutionary process of its own. Memes are the units of selection (or memetic systems, or subcultures) - that is, we have ideologies and belief systems and cultural mores that, in effect compete with each other and are one level removed from genetic evolution.

At yet another level, our capacity to choose makes us each an individual agent in a game that initially only had one player: genetic evolution. But when we were able to create culture we created a cultural (or memetic) evolution. And the very faculty that can create idea systems has choice and that makes each individual able to evolve in their own interactions with the extended phenotype, their self, and the greater environment.

So we have genetic evolution, memetic evolution and personal evolution. Each system is an agent. Genetic evolution is the base the others rely on. Each, as an agent, interacts with the others. Genetic evolution serves the purpose of the gene's teleological purpose. From the genes point of view, we are its means of getting itself leveraged into its next generation. Each sub-culture or belief system can be seen as a collection individual units of belief that work together well enough to have stayed cohesive and recognizable as they get passed from generation to generation, or person to person. They can be seen as using us as vehicles to bring about their propagation and spread in lieu of their competitors. Then there is "I" - the choosing agent focusing my awareness and acting and in doing so, become an active force modifying the direction that I would have taken had I remained a complete toy to the genes or memes that would move me this way or that. My character, my psychological habits, my key values are the phenotypical expressions of my choices that serve to generate selective repetition through time. I am my own next generation and I leverage my intellectual 'genes' into the future rather than a new person or new culture. The trickiness of this evolution arises out the nature of choice. It means that we set our own standard of selection with our deepest values and our consistency of integration. It means that we can program ourselves to be full of bugs and self-destruct (we have all seen individuals that chose that personal evolution) or to develop into efficient seekers of long-term happiness.

Post 9

Wednesday, August 6, 2008 - 8:38am

The amazingly prescient Aristotle had this question wrapped up 2000 years ago.

"All human behavior is one of four things, chance, nature, habit, or choice"

The "Nature vs Nurture" debate is not only a false dichotomy � why is 'choice' (fully informed volitional conscious choice) not included? it's always either your environment forces you to act in a particular way or your natural genetic disposition forces you to act in a particular way � either way you are forced, they pretend like free will does not even exist.

Rand�s suggestion that humans are �blank slates� was a figurative one, not a literal one. It�s clear that genes can influence behavior as any cursory understanding of genetics will show (if one of a pair of identical twins is gay, for instance, there is a 50% chance that the other one will be) but it is equally clear that none of these genetic relationships to behavior are absolute. In all cases it seems an individual can choose to over come their predisposition from their genes, or even their social indoctrination can convince them to overcome a genetic predisposition. The correct answer then is that all human behavior is a complicated interaction of these four things; and science clearly shows this as well. The question is additionally complicated with the emergence of epigenetics, where behavior can actually alter genetic expressions which are then heritable (fascinating stuff!!!)

I believe the evidence shows that each successive aspect of behavior in this hierarchy can over ride the previous. If you attempt to embrace randomized behavior your genetic influences take over. Habit�s can then over ride your genetic influences, and deliberate conscious choices can then over ride genetic influences and social habitualization. People who live a generally �un examined� life will end up acting as a mix of their genetic predispositions and habitual indoctrination from their culture (the root of the focus on only �Nature vs Nurture� I think)

Post 10

Wednesday, August 6, 2008 - 9:02am

"The "Nature vs Nurture" debate is not only a false dichotomy � why is 'choice' (fully informed volitional conscious choice) not included?"

Because it's not a meaningful concept. As a scientist if someone is behaving in a certain way - say, being an alcoholic, or being gay - you might want to know why. And you can do various studies to find out whether there are genes, or environmental factors, which make one person gay and another not. But if someone comes along and says "He's gay because he chooses to be gay", that's no explanation at all. We already know that he chooses to be gay, in the sense that no-one is holding a gun to his head. We want to know *why* he "chose to be gay" while the guy who lives next door didn't.

The answer might be genes or it might be environment or it might be both (in most cases, it's both), but it can't be neither. Some people might be born with a genetic risk for alcoholism, but manage to avoid becoming an alcoholic. Good for them? Maybe, but I would say - lucky for them that they happen to have other genes for a strong willpower. Or that they had a sound upbringing. Or that they happened to see an alcoholic bum one time and it shook them into becoming teetotal.
(Edited by Jeremy B on 8/06, 9:03am)

Post 11

Wednesday, August 6, 2008 - 9:51am

Jeremy, your post has some major contradictions. You said:

Because [choice] [i]s not a meaningful concept

And then said:

lucky for them that they happen to have other genes for a strong willpower

genes for a strong will power? Are you then suggesting that a strong will power actually pertains to behavior? If so, it certainly is a meaningfull concept, regardless of whether 'genes' made you come to an informed conscious choice or not.

Of course genes do play a role in choice at some level because at the root of all our physiological capacities is our genetic makeup, the very ability to make choices which come from reacting to values and perceptions is from our physiology which is constructed according to our genetic code. Genes enable us to make choices, however they do not always tell us WHAT to choose!, nor are all of our choices directly related to genetic influence and / or environmental social habitulization.

But if someone comes along and says "He's gay because he chooses to be gay", that's no explanation at all.

Actually it is just as valid an explanation as "He is Gay because of his environment" and he is "Gay because of his genes" He can be Gay because of choices and values he has integrated throughought his life that do not pertain to his environment nor his genetic makeup. This is clearly evidenced by the fact that some societies throghout history have adopted homesexual and bisexual behavior as norms, this was not because there was some wierd pollen floating around making them gay, nor because they expressed an entirely unique genetotype which made them 'choose to be gay' but because culturally they accepted the idea more openly than other cultures, and the associated values were integrated within individuals.

A person may have a strong genetic predisposition to heterosexuality, and when raised in a conservative culture which did not encourage pyschological self examination nor embraced a value based view of ethics would have no problem continuing to be a heterosexual.

A person without a strong genetic predisposition toward heterosexuality or homosexuality raised in that same culture would probably end up 'choosing' to be heterosexual, that same person raised in a culture which openly accepts bisexuality would probably be bisexual.

But these are not 'choices' in the sense we choose what time to get up in the morning, they are choices in the sense we choose what we find humorous; a culimnation of millions of small choices we make throughout life and of the ideas and values we integrate throughout our lives and to what degree they are integrated.

A person with a strong genetic predisposition toward homosexuality would have an extremely difficult time choosing to be heterosexual, especially if they fundamentally do not want to integrate that value. Someone without as strong of a predisposition might be able to, hence the sometimes 'successful' nature of religious sexual re-orientation 'camps' - these people choose to value their social habituatalization values over their genetic predisposition, and many claim to no longer be gay and are never observed in engaging in homosexual behavior. You may claim that this merely means they are 'suppressing' their true 'nature' (surely some are) but this is a presupposition that genetic predisposition is the end all in human behavior, the scientific evidence clearly shows otherwise, and again, the cultural historical evidence shows otherwise as well.

Sexual orientation is probably one of the most difficult of the genetically predisposed behavior one could alter, I can't speak to the degree of difficulty but can only point to the evidence showing it is possible. And this is probably dependant on the degree of the predisposition as well. The same could not be said of all genetically predisposed behavior though.

The answer might be genes or it might be environment or it might be both (in most cases, it's both), but it can't be neither

It certainly can be neither, some choices we make in life are or can be entirely removed from genetic or environmental influences, this depends on the degree to which you embrace living an 'examined' life.

Some people might be born with a genetic risk for alcoholism, but manage to avoid becoming an alcoholic. Good for them? Maybe, but I would say - lucky for them that they happen to have other genes for a strong willpower. Or that they had a sound upbringing. Or that they happened to see an alcoholic bum one time and it shook them into becoming teetotal.

Or some may have weighed the positives and negatives of consuming alchohol and made a concious choice accordingly - this is, in fact, what I did, and I was 30 years old before I had ever consumed a drop of liquor, which I started to because of the tremendous scientific evidence showing the benefits of Resverestrol (found in some red wine) on general health and the positive effects very moderate alchohol consumption has on minimizing heart disease. Oh, but I suppose I have a gene for making long deliberative choices eh in regard to inconsequentials like alchohol consumption?

Though you pay lip service to the idea of choice, your are basically a scientific determinist.

Post 12

Wednesday, August 6, 2008 - 5:16pm

I am bisexual because I like the hat that they give you along with membership.

And enough about gay twins, already. What about triplets?

Seriously, though, I think Jeremy may be talking about statistical correlations. When dealing with large numbers of people, vagaries of individual choice ten to cancel out, while trends such as genetic disposition or upbringing become more prevalent. In a statistical sense, "chose to be homosexual" becomes less meaningful than "has a gene that makes the sweat of others of the same sex smell good" or "got sent to prison for life" or "is in the navy."

Volition is the ability to chose between multiple options when outside circumstances do not force one path over another. Faced with vanilla icecream or chocolate, I can choose either, both, or neither. But I can choose. Neither my genes (which may make me crave fat) nor my environment can force me to eat or not eat or to eat one or the other. But volition is something that we have by our natures. Hence our genes "force us to be free." Environment can encourage habit. But the most important part of our environment is past choice. Choice is a self-encouraging habit.

(Edited by Ted Keer on 8/06, 8:06pm)

Post 13

Saturday, August 9, 2008 - 5:51am

"Though you pay lip service to the idea of choice, your are basically a scientific determinist."

Yes I am, and I hope I didn't give the impression of even paying the idea of choice (as an explanation of behaviour) even lipservice!

"He can be Gay because of choices and values he has integrated throughought his life that do not pertain to his environment nor his genetic makeup. This is clearly evidenced by the fact that some societies throghout history have adopted homesexual and bisexual behavior as norms, this was not because there was some wierd pollen floating around making them gay, nor because they expressed an entirely unique genetotype which made them 'choose to be gay' but because culturally they accepted the idea more openly than other cultures, and the associated values were integrated within individuals."

Of course - in some cultures homosexuality is more accepted, but the culture one is born into is part of one's environment. Environment includes the social environment. You don't choose which culture you're raised in.

"Or some may have weighed the positives and negatives of consuming alchohol and made a concious choice accordingly - this is, in fact, what I did, and I was 30 years old before I had ever consumed a drop of liquor, which I started to because of the tremendous scientific evidence showing the benefits of Resverestrol (found in some red wine) on general health and the positive effects very moderate alchohol consumption has on minimizing heart disease. Oh, but I suppose I have a gene for making long deliberative choices eh in regard to inconsequentials like alchohol consumption?"

Maybe, but I think you certainly lack the genes (which are starting to be identified) for impulsive decision-making. You took a considered, concious decision, but some people just can't do that. you weighed the positives and negatives and decided not to drink, but the very fact that you did that, was not something you chose to do (I'm sure you can see that an infinite regress of choices would occur if you say that we choose to do everything. Do we choose to choose to choose to do...?)

"I am bisexual because I like the hat that they give you along with membership."

You've convinced me, where do I sign up?

Post 14

Monday, August 11, 2008 - 7:53am