Do Genes Make the Person?

17 April 2005

Do genes make the person? If you listen to popular press reports of new genetic discoveries coming out at fairly rapid pace, you certainly might think so. Lung Cancer Gene! Gay Gene! Genius Gene! Little wonder that many people believe -- or should I say fear? -- that genes somehow directly and invariably determine who we are. One has visions of being able to choose the IQ, personality, and physical attributes of one's offspring with the ease and reliability with which one chooses a meal at a good Chinese restaurant. As Stephen Jay Gould once put it, "If we are programmed to be what we are, then these traits are ineluctable. We may, at best, channel them, but we cannot change them either by will, education, or culture." But even a brief perusal of the scientific and/or philosophical literature about the role of genes in determining who we are reveals that at least in this strong form, genetic determinism has little or no basis in either scientific fact or theory. Genes clearly play an important causal role in the development of a phenotype. And according to one standard, but by no means universally endorsed conception of evolution, genes are the units on which natural selection operates. But none of that entails rigid and direct genetic determinism. So what, really, is the big fuss?

That's precisely the question we hope to get clear about in this episode. Our guestJohn Duprethinks the power of genes to make the person has been vastly oversold. Here's how he puts it in his book,Human Nature and the Limits of Sciencein the context of discussing the idea that genes build brains:

We can now see how massively simplistic is the assumption that genes build brains. Obviously genes can do nothing, let alone build a brain, on their own. To build a human brain the genes must be properly located in a cell complete with all the properly functioning extranuclear machinery; the cell must be properly positioned in the uterus of a human female; and the child must be born into a social setting that will provide an extremely complex set of stimuli to the human organism in which the brain is located. So is there really any sense in which genes build brains in which it is not equally true to say that wombs build brains, or even schools build brains?

For Dupre the answer to this last question is clearly no. And there is surely a sense in which he is right. I think probably everyone who has thought much about it would concede his central point, since everyone agrees that genes are not, to coin a phrase, self-developing. To get from a gene to a phenotype often takes a lot of steps. And all sorts of things -- things in which the gene may have no direct role -- have to go right along the way. So again, it's fair to ask, exactly what the fuss is all about.

基因如何帮助形成一个人,至少在大众理解的基础上,有一件事可能就是基因密码的概念。有人设想,有一种类似“基因语言”(LOG)的东西,其中明确规定了发育中的有机体的某些生物命令。“你会得到一颗心的!”“你会有两个肾。”“你的智商将达到129!”“你会倾向于犯罪的!”“你会得阿尔茨海默病的!”等等。尽管人们可能承认基因需要帮助才能将它们的指令转化为有机体中的表现型特征,但它们仍然是这些特征的最终来源,因为它们为这些特征“明确编码”。就像你不能让一个程序在电脑上运行,除非你编译或解释它,所以你不能把一个遗传程序转换成表现型,除非你编译或解释它。如果这是正确的,也许我们不应该从杜普雷的言论中得到太多安慰,因为基因并不比子宫或学校更能构建大脑。 Wombs and Schools are just part of the machinery for interpreting or compiling of the genetic program.

我认为这是不对的。此外,我相信我们会让Dupre说更多关于为什么这不是正确的方式来思考基因在导致表型方面的独特作用。如果真有LOG(基因的语言)这种东西,那么LOG可以说是用非常贫乏的词汇写成的。粗略估计,LOG的丰富程度可能仅够表达关于氨基酸序列的“陈述”。这并不是故事的全部,因为有些东西决定了各种氨基酸序列的排列顺序,似乎确实有基因起着这个作用。无论如何,从精心安排的氨基酸序列到构建像人脑这样复杂的东西,都是一个非常非常漫长而复杂的旅程。当然,有正常和相对稳定的发育途径在基因之间进行中介,它们带有构建氨基酸的编码指令,以及任何大规模的表型特征。为了一些解释的目的,它可能是有用的解释,作为“黑盒子”的中介发展路径,我们不需要看。据我所知,这正是所谓自然选择单位的“基因选择学家”倾向于做的事情。但即便如此,也远非认可基因决定论,或将基因提升为造就我们的独特特权来源。 Even the genetic selectionist, who claims that only genes are selected for, has to concede that development is not the business of the gene alone.

There's a lot more to say here. I'm sure we'll say lots of it on the air today. And I'm sure both John and I and hopefully you too will learn a lot from our conversation with John Dupre. But I'm tempted to conclude already, that the whole boogieman of genetic determinism is based mostly on misunderstanding. Dan Dennett is probably right to say that no one, at least no serious scientist, seriously endorses genetic determinism. It certainly is hard to find anyone who admits to being a genetic determinist. S0 exactly howdoesa view that has no hold in the scientific community take on such a life of its own in the popular imagination?

It doesn't follow, though, there are no remaining controversial issues about genes and their role in making us who we are. Dupre, for example, holds pretty dismissive views about the explanatory promise of Evolutionary Psychology, a discipline that I myself find rather intriguing. His dismissal is partly based on his rejection of what he thinks is their misappropriation of genetic explanation. I'm not sure he's right about that and I'm not sure that evolutionary theory has as little to teach us about universals of human nature as he apparently believes. But we'll see.

Comments(11)


Guest's picture

Guest

Monday, April 18, 2005 -- 5:00 PM

It was unfortunate that you didn't have time to re

It was unfortunate that you didn't have time to really flesh out with John Dupre about the implications of his ideas for 'genetic engineering' and such. Perhaps it is incorrect to extend what was basically a conversation about human developement to plant gene engineering or animal gene engineering, but it seems to me that there must be similar processes in all living things. If the gene is not the only mechanism that makes a trait express in an individual organism, than it seems to me real hubris to think that we have control over the effects of genetically modified organisms.

Guest's picture

Guest

Monday, April 18, 2005 -- 5:00 PM

Looks like an entirely terminological debate to me

Looks like an entirely terminological debate to me.
Nobody is unsure here around what happens when a brain develops, or than our physical makeup is contingent on our genes, including our brains.
If you don't like saying "genes maketh the man", then don't say it. In my own words, "Kabloo, ignagger fakwump. Blug blug igzoo". You didn't understand that? Well, that's because language is arbitrary. I'm *still not wrong* about genetics. A rose by any other name would still wilt after 5-7 days from delivery.
-MP

Guest's picture

Guest

Monday, April 18, 2005 -- 5:00 PM

I do not know if genes make the man, but I have a

I do not know if genes make the man, but I have a question. How far does education go in developing a person? Can education improve all parts of the mind? Kant stated that education could not help develop judgment, but I also heard that Kant was a racist. In my view Will, Eros, and Reason are the most powerful parts of a human being, but I believe that artificial machines will be able to control all of the physical including the brain. Genes make up the genotype and phenotype of the human being, but I would be more concerned with the control of the mind. The mind can always use reason and will to manipulate genes through science, but what will the mind do when machines control the brain? If the spirit exists it has to go through the brain to produce action. If the brain is locked by a microchip, then it does not matter how much the spirit wants to move the arm if Will cannot go through brain. Artificial Intelligence, Genetics, its all about control. The most important control is the control of consciousness.

Guest's picture

Guest

Tuesday, April 19, 2005 -- 5:00 PM

"S0 exactly how does a view that has no hold in th

"S0 exactly how does a view that has no hold in the scientific community take on such a life of its own in the popular imagination? "
Journalists, for one. I think most educated people sense the slippery slope from the denial of free will to the social breakdown that would occur if we were deemed to not bear responsibility for our actions. Journalists pose genes as a threat to free will, and voila, Time and Newsweek have catchy cover stories.
当真正的学者感到这种恐惧时,根本的问题就来了,而他们的反应是从恐惧退回到对所涉及的科学细节的质疑。并不是说我们不应该质疑科学。但是,如果动机是出于哲学目的,而不是出于冷静的理性探究,我们就会让这些腐败的表情包进入专家们的头脑,然后进入外行的头脑,因为对科学的攻击来自学术权威。
Steven Pinker and (especially) Daniel Dennett take extraordinary pains to try and put thinking people at ease - modern science is not at odds with free will in any meaningful sense.
Daniel Dennett gave a great interview on these subjects (free will, determinism, evolution, etc) to Reason a little while back, it's a good introduction to some of his work as well:
http://www.reason.com/0305/fe.rb.pulling.shtml
-Steve

Guest's picture

Guest

Friday, April 22, 2005 -- 5:00 PM

Hey! Why is the latest show not up on the website

Hey! Why is the latest show not up on the website yet? Did you guys have a show on Genetics and Determinism?

Guest's picture

Guest

Monday, April 25, 2005 -- 5:00 PM

Ken's initial point about the way the media portra

Ken's initial point about the way the media portrays "genetic determinism" (a misnomer indeed) made me want to plug a panel discussion on "Mind and Brain in the Media" that I have organized at the 2005 meeting of the Society for Philosophy and Psychology (http://www.hfac.uh.edu/cogsci/spp/wwwanlmt.htm).
I worry that the media presents to the general public research in evolutionary psychology/genetics, neuroscience, and other cognitive sciences in a way that is sometimes misleading and potentially dangerous given the important ethical and legal issues affected by people's conception of human nature.
We'll be discussing the role philosophers of mind and cognitive scientists should play in having their research disseminated by the media (and popular works). Panel members include Paul Bloom (psychologist), Owen Flanagan (philosopher), Daniel Povinelli (cognitive evolution), and Dan Lloyd (philosopher). I'd like to get a science journalist there but have not had any success yet. Maybe Ken or John know someone??

Guest's picture

Guest

Monday, October 24, 2005 -- 5:00 PM

They don't! But they do start the process of makin

They don't! But they do start the process of making the person.

Guest's picture

Guest

Saturday, April 15, 2006 -- 5:00 PM

Well i don't really know whether genes makes the p

Well i don't really know whether genes makes the person but this thing is for sure that they make up the genotype and phenotype of the human being.

Guest's picture

Guest

Saturday, April 15, 2006 -- 5:00 PM

I have come to the conclusion that neither genes n

我得出的结论是,基因和教养都不能造就一个人。更强大的影响是文字和阅读的力量。你能想到任何没有词的东西吗?

Guest's picture

Guest

Monday, April 17, 2006 -- 5:00 PM

是的,我能。我称之为“无法命名”......糟糕!B

是的,我能。我称之为“无法命名”......糟糕!
But with regard to whether the genotype determines the phenotype the answer is obviously no, since some organisms develop dramatically different forms and behaviours depending on their environment. On the other hand the genotype does limit the phenotype - I have already lasted more than seven days without wilting but alas I will never smell like a rose.
From listening to the show, I had to agree with Ken and John when they appeared to be suggesting that John Dupre was exaggerating the literalness of the public understanding of "gene for" this or that. I think most of us are aware that the situation is often much more complicated and that the "gene for" is really understood as a proxy for "inherited biological tendency to" - but even if the misconception is real I am not sure how much it matters. The fact that the details are often expressed simplistically (or even understood that way) should not be used to deny the truth that many of our characteristics *are* determined at conception (whether by genes or whatever).
Yes it is unfortunate when determinism is assumed for characteristics to which it does not apply - or to which it does apply but only in a statistical sense, and especially when such assumptions are used to justify socially harmful attitudes and policies, but it does not make sense to deny the possibility just because we don't like the way some people abuse it.
I do wish there had been more time to follow up on Ken's concluding reference to the determinism/freedom issue.
Thanks for fixing the link. It's great to be able to enjoy these shows so long after the fact.