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On arguing by analogy

Filed under: — gavin @ 2 September 2014

Climate blogs and comment threads are full of ‘arguments by analogy’. Depending on what ‘side’ one is on, climate science is either like evolution/heliocentrism/quantum physics/relativity or eugenics/phrenology/Ptolemaic cosmology/phlogiston. Climate contrarians are either like flat-earthers/birthers/moon-landing hoaxers/vaccine-autism linkers or Galileo/stomach ulcer-Helicobacter proponents/Wegener/Copernicus. Episodes of clear misconduct or dysfunction in other spheres of life are closely parsed only to find clubs with which to beat an opponent. Etc. Etc.

While the users of these ‘arguments’ often assume that they are persuasive or illuminating, the only thing that is revealed is how the proposer feels about climate science. If they think it is generally on the right track, the appropriate analogy is some consensus that has been validated many times and the critics are foolish stuck-in-the-muds or corporate disinformers, and if they don’t, the analogy is to a consensus that was overturned and where the critics are the noble paradigm-shifting ‘heretics’. This is far closer to wishful thinking than actual thinking, but it does occasionally signal clearly who is not worth talking to. For instance, an article pretending to serious discussion on climate that starts with a treatise about Lysenkoism in the Soviet Union is not to be taken seriously.

Since the truth of falsity of any scientific claim can only be evaluated on it’s own terms – and not via its association with other ideas or the character of its proponents – this kind of argument is only rhetorical. It gets no-one closer to the truth of any particular matter. The fact is that many, many times, mainstream science has survived multiple challenges by ‘sceptics’, and that sometimes (though not at all often), a broad consensus has been overturned. But knowing which case is which in any particular issue simply by looking for points of analogy with previous issues, but without actually examining the data and theory directly, is impossible. The point being that arguments by analogy are not persuasive to anyone who doesn’t already agree with you on the substance.

Given the rarity of a consensus-overturning event, the only sensible prior is to assume that a consensus is probably valid absent very strong evidence to the contrary, which is incidentally the position adopted by the arch-sceptic Bertrand Russell. The contrary assumption implies there are no a priori reasons to think any scientific body of work is credible which, while consistent, is not one that I have ever found anyone professing in practice. Far more common is a selective rejection of science dependent on other reasons and that is not a coherent philosophical position at all.

Analogies do have their place of course – usually to demonstrate that a supposedly logical point falls down completely when applied to a different (but analogous) case. For instance, an implicit claim that all correct scientific theories are supported by a unanimity of Nobel Prize winners/members of the National Academies, is easily dismissed by reference to Kary Mullis or Peter Duesberg. A claim that CO2 can’t possibly have a significant effect solely because of its small atmospheric mixing ratio, can be refuted as a general claim by reference to other substances (such as arsenic, plutonium or Vitamin C) whose large effects due to small concentrations are well known. Or if a claim is made that all sciences except climate science are devoid of uncertainty, this is refuted by reference to, well, any other scientific field.

To be sure, I am not criticising the use of metaphor in a more general sense. Metaphors that use blankets to explaining how the greenhouse effect works, income and spending in your bank account to stand in for the carbon cycle, what the wobbles in the Earth’s orbit look like if the planet was your head, or conceptualizing the geologic timescale by compressing it to a day, for instance, all serve useful pedagogic roles. The crucial difference is that these mappings don’t come dripping with over-extended value judgements.

Another justification for the kind of analogy I’m objecting to is that it is simply for amusement: “Of course, I’m not really comparing my opponents to child molesters/food adulterers/mass-murderers – why can’t you take a joke?”. However, if you need to point out to someone that a joke (for adults at least) needs to have more substance than just calling someone a poopyhead, it is probably not worth the bother.

It would be nice to have a moratorium on all such analogical arguments, though obviously that is unlikely to happen. The comment thread here can assess this issue directly, but most such arguments on other threads are ruthlessly condemned to the bore-hole (where indeed many of them already co-exist). But perhaps we can put some pressure on users of these fallacies by pointing to this post and then refusing to engage further until someone actually has something substantive to offer. It may be pointless, but we can at least try.

210 Responses to “On arguing by analogy”

  1. 101
    Bill Hurley says:

    Just wanted to note that whenever I hear “can’t convince, so ignore”, I cringe. That’s what the environmental community has done in mass since I can remember. And the result has been to have more and more people “not getting it.”

    Please remember that if you don’t counter stupid non-reason type sentiments, and you don’t respond – those who are listening quietly in the background form the wrong conclusion. And they then vote in Ted Cruz and James Inhofe. (IE those that can block correct actions.)

  2. 102
    Chris Dudley says:

    John (#80),

    Denial is an emotional response to change. Anti-Semites, angered that their prejudice is under attack, deny the holocaust happened. Racists, angered that Obama was elected president, deny he was born in America. Children facing the divorce of their parents, deny it is happening. Those with substance addictions deny they have a problem to avoid change. Conservatives, frightened of liberals changing society, deny reasons to change exist, such as global warming.

    How we respond to denial will depend on circumstances. With the Holocaust deniers, is is a useful marker to identify hate groups and track their activities to avoid domestic terrorism incidents. The same may go for birthers. With children, being present and consistent and acknowledging their grief is best. Response to the substance issues range from intervention to disentanglement. On climate change, politically isolating deniers by exposing them to ridicule and associating them with corruption and the constellation of hateful views held by reactionaries is probably best. For example, any mention of Monckton should say that he falsely accuses young people concerned about climate change of being Nazis. Any mention of Ken Cuccinelli should note that he took gifts from Jonnie Williams. Any mention of coal PACs should mention that they mistreat veterans by forging letters from their organizations. Climate change denial is essentially a character flaw and it will be associated with others. Those whose first instinct is to accuse climate scientists of dishonesty are likely channeling their own character bent. Needing to move forward on climate action, dismissing deniers from the process as adroitly as possible should be the adopted tactic.

  3. 103
    Radge Havers says:

    DF @ ~ 97,

    So FWIW, here’s how I see it in a nushell. Analogies are inherently weak. You can put them on a spectrum from useful to awful. That and their perceived, exceptional widespread abuse (which heavily weights the awful end) makes them different, and is cause to give them special attention.

    I suspect that they represent a special category of thinking and are hard wired into our prescientific brains, but I’m out of my depth on that point.


    NickC @ ~ 95

    Yes, professional scientists spend hard decades training their minds to do what they do. It’s specialized training. Here’s an analogy, if you haven’t spent years in the gym doing rigorous training, do you think that you can just walk in and deadlift a 1,000 lb. loaded barbell? Come on.

  4. 104
    Hank Roberts says:

    Aside for “John Smith” — the link to the article describing PR/industry use of ‘denier’ and ‘Nazi’ rhetoric, before climate change became an issue, sometimes appears paywalled and sometimes free full text.

    If you care to look it up, search by title and DOI number:

    Tob Control 2008;17:291-296 doi:10.1136/tc.2007.024653
    “Nicotine Nazis strike again”: a brief analysis of the use of Nazi rhetoric in attacking tobacco control advocacy

    The tobacco industry and smokers’ rights groups21–24 have evoked the rhetoric and symbolism of Nazi Germany to describe public health authorities and advocates as oppressors who discriminate against smokers since at least the late 1960s. Although “Nazism” and “fascism” are not synonymous, they are often seen by the public as being the same, and were probably conflated in their use against tobacco control to evoke the same negative feelings and reactions. … This article traces how the tobacco industry developed and promoted Nazi and health fascism rhetoric for decades around the world.”

    A commentary article at gives more dates and references to the use of claims of “health fascism” by the tobacco industry even earlier.

    It’s rhetoric used by the industry; you’ve been fooled. Don’t be fooled again.

  5. 105
    Hank Roberts says:

    A more stable full text of that same article is here

    Nazism appears: the 1960s cancer debate

    After the 1964 US Surgeon General’s report27 linked smoking and cancer, the Tobacco Institute (TI), the US tobacco companies’ political and public relations arm, worked to undermine the credibility of researchers supporting this link.28 In 1967, the president of the Tiderock Corporation, one of the TI’s public relations agencies,29 published an article in Esquire magazine that the TI widely distributed to the media30–32 comparing non-smokers and tobacco control measures to Hitler and the Nazi regulations ….”

    Citations are linked in the original text.

  6. 106
    dcpetterson says:

    Analogies are useful as a way of introducing a concept.

    Gavin, I believe what you are (rightly) objecting to is the use of analogies as ad hominem devices. It does not advance anyone’s argument to use analogies as a way of discrediting either the other person, or the other person’s position, in lieu of addressing the data and rational arguments the other person presents.

    When used as a means of attempting discredit, analogies confuse and obfuscate rather than illuminate. They are often effective for this purpose, in a practical sense, because most people aren’t trained in logic and so are vulnerable to this type of fallacy. If one’s goal is to present truth and reason, analogies as ad hominem tools are offensive. If one’s goal is to advance a viewpoint, regardless of that viewpoint’s relationship to reality, fallacious analogies do sometimes have the desired impact.

    None of which touches on analogy as a pedagogical tool, or as a way of simplifying complex concepts as a first-pass approximation. Indeed, it can be argued that all language is analogy (the words we use stand in the place of the objects and actions we are discussing) and so some level of analogy is unavoidable.

    The problem is simply an extension of Godwin’s Law. It is an attempt to tie the other side to something unpleasant, and so to win an argument on some basis other than a consideration of actual relevant evidence and logic.

  7. 107
    Steve Fish says:

    Re- Comment by NickC — 7 Sep 2014 @ 2:01 AM, ~#96

    Your comment about Gavin, “those who disagree with him do not dispute the science but more the judgement calls made about how limited evidence is interpreted,” along with your other assertions suggest that you don’t think that interpretation of data is science. Do you have the same attitude about the expert interpretation of data about your tests by an oncologist, an engineer about a bridge or building design, an accountant about business/tax practices, or a lawyer regarding the facts of a case? These are not analogies, but constitute a direct challenge to your assertion that an amateur opinion is as valid as that of an expert on a subject. A non-scientist could very well have some expertise in a complex scientific topic, but how would you verify this? I request that you provide some specific examples of your complaint.


  8. 108
    Mal Adapted says:

    Erich Zahn:

    The Republican leaders who disgust you do not care if you think they are stupid. They know that when they appear anti-science or anit-intellectual it drives your side crazy and ties you up in knots ( Teacher, did you hear what Bobby-Joe said? Aren’t you going to give him an F?). This is fine with them if it delays implementation of knee-jerk taxes and new government spending. (because we have to do something!). Maybe your opponents are smarter than you think, and maybe you should think hard about what really needs or can be done, once the last holdout agrees to the answer to the first question.

    I’m not a member of any “side” but my own, and what ties me up in knots is that AGW-denying politicians are only superficially motivated by ideological opposition to taxes and government spending. Rather, they are dancing to the tune played by fossil-fuel billionaires, who’ve made their private fortunes by socializing the cost of climate change, and who are willing to divert a fraction of their revenue streams to obstruct any government action that threatens those revenues. It’s been abundantly documented that fossil-fuel money influences politicians not only through campaign contributions, but by supporting an entire industry aimed at confusing the public about the overwhelming scientific consensus on AGW and the motives of anyone who suggests that greenhouse gas emissions should be abated.

    Pseudo-skeptics facilely dismiss such claims as conspiracy theories, but “conspiracy” implies something illegal and secret, and the connection between fossil-fuel money and AGW denial by politicians is neither. Far from being secret, much of the documentation for the claim is in the public record, at least up until the last few years. After all, within broad limits it’s legal in the U.S. to make virtually unlimited political contributions, and to fund, craft and disseminate sophisticated disinformation about the scientific case for AGW and the people who accept it.

    This is all common knowledge to RC regulars, but since you appear to be a newcomer here, I’ll cite two sources: the series of reports in the New Yorker magazine by Jane Mayer, beginning in 2010 with Covert Operations; and Institutionalizing Delay, a peer-reviewed article published last year by Robert Brulle in the journal Climatic Change.

  9. 109
    Mal Adapted says:


    Is the whole 7% trained scientist thing a bit arrogant? Assuming a large proportion of non-scientists to be bereft of any skill (not in the “models have skill” sense) in weighing argument is clearly nonsensical. Gavin, for example, has a line of argument about the merit of paleo climate inferences, those who disagree with him do not dispute the science but more the judgement calls made about how limited evidence is interpreted. One can agree on the science but not the interpretation.

    There is also an assumption that the 7% have had some sort of special training to join the rarefied ranks of data interpretation, and enter a professional realm where the mere practice of the discipline imbues one with an unbiased altruistic imperative free of any need to employ analogy.

    Your arguments may seem reasonable to someone who hasn’t had that special training. Especially at the professional level, deciding which of two or more competing scientific claims are correct does, in fact, require skills beyond those needed for daily existence.

    Consider Feynman’s dictum “The first rule [of Science] is not to fool yourself, and you are the easiest person to fool.” An individual scientist might be convinced her findings are correct because she’s applied the most exacting standards of empirical rigor to her research, but she might still be fooling herself. Before she can say she’s made a lasting contribution to scientific knowledge, she has to convince her peers, who aren’t just the people she meets on the street, but the other scientists who’ve been through the same rigorous training, studied the same evidence, and subjected themselves to the same unsparing peer criticism. They are the ones who can best find the errors she’s overlooked.

    Gavin’s inferences from paleo-climate evidence are judgement calls in a sense, but his judgement is usually supported by that of other trained climate scientists, and if not he knows better than to insist he’s correct. It isn’t just a matter of “he said, she said”. To be taken seriously, a scientist who disagrees with Gavin’s judgement will have to persuade their peers, and analogy will only go so far in the attempt.

  10. 110
    Jim Larsen says:

    97 DF asked, “When is it ok to use an incorrect argument? Are any of the fallacies more appropriate than the others?

    Analogies aren’t valid arguments, but they are great educational tools. That makes discussion by analogy more appropriate than most (all?) other fallacies. Just remember, it won’t hold up in “court”.

  11. 111
    John J says:

    It’s “Helicobacter” (from helix), not “Heliobacter”.

    Over 50% of the global population have Helicobacter Pylori but fewer get gastritis. So, what gives?
    Sapolsky has shown that those with prolonged stress, have a weakened immune system.
    Stress means that your body produces stress hormones that gets your body to focus for survival.
    When stressed, digestion is on pause because digestion is not necessary when you try to survive from a lion chase.
    Similarly, the immune system is suppressed.
    Social animals like humans tend to feel prolonged bouts of stress which suppresses the immune system and can let Helicobacter to take control of the stomach.

  12. 112
    T.T.T says:

    Ok, just one more time. I’ve only had two glasses of wine so far, I swear, I think, so I’m ok, I think. This is not my comment on my thoughts. This is my request. Requests to you as the educated in the public forums.

    On the public forums, not necessarily this blog but in general, whether it’s on th web or at some actual meetings with the public. When you encounter the talking points, help them articurate their points. Specially in physical real meetings, ‘earnestly’ help them to articurate their arguments of talking points because most people don’t know why they say what they say and don’t know the basic science based on it if there’re any.
    You help them earnestly to realise what they’re saying, then they’d appreciate your help and respect you that you do understand what they’re trying to say. Now they’re ready to listen to you what you’ve got to say.

    When you debunk the talking points please just don’t just debunk but also try to show how to look at things scientifically. Because you can’t debunk every and each talking point every time again and again. They will never quit.
    My point is you give a man a fish you feed him for a day but you teach him how to fish … (another analogy). I know it seems so exhausting and daunting. I don’t mean every time but to keep in mind. I can’t do it because I’m not educated, well read, learned nor a scientist.

    Remember, in evolution there are mostly the fundamental religious and in climate change, the religious and agnostic (closet religious) libertarians.
    And one more thing, there are seasoned trained trolls and ordinary people. No , we can’t tell. I’d think we shouldn’t presume unless you know them for sure, but then again there are people around listening in.

  13. 113
    Chris Dudley says:

    I’d like to emphasize again the importance of analogy in scientific explanation. Science is sometimes understood and sometimes merely described. Feynman expresses a frustration with QM: “One might still like to ask: “How does it work? What is the machinery behind the law?” No one has found any machinery behind the law. No one can “explain” any more than we have just “explained.” No one will give you any deeper representation of the situation. We have no ideas about a more basic mechanism from which these results can be deduced.”

    To explain QM, you have to start out with something like “Consider a spherical pink elephant that is square and covered with zebra stripes….” The analogy fails. So, QM is described, and it works and we know how to make it work, but venturing into the question of why it works can be frustrating.

    But most of the time an analogy like a bathtub that is filling with the drain partly open (carbon in the atmosphere) or a higher floor from which to start a stair case (how the lapse rate start point affects surface warming) is a really good way to gain understanding of the sort that can build into further understanding. Watch an AP physics test and you’ll see people moving their right hands in circles to understand magnetic fields. The analogy is pervasive is science.

  14. 114
    wili says:

    Caldeira doesn’t seem to mind using strongly worded analogies to get his point across:

    “If you’re talking about mugging little old ladies, you don’t say, ‘What’s our target for the rate of mugging little old ladies?’ You say, ‘Mugging little old ladies is bad, and we’re going to try to eliminate it.’ You recognize you might not be a hundred per cent successful, but your goal is to eliminate the mugging of little old ladies. And I think we need to eventually come around to looking at carbon dioxide emissions the same way.”
    Dr. Ken Caldeira

  15. 115
    wili says:

    Nor does Piers Foster:

    “Compare climate change to a train trundling across America. Some way down the track, we are not sure how far, the bridge is out and disaster looms. Do we want to be the ones to sit back and watch the train wreck, or do we want to be the hero?”
    Professor Piers Forster

  16. 116
    calyptorhynchus says:

    I disagree, I think analogies might change a few minds, and perhaps the degree of fury they evoke in opponents is an index to their effectiveness.
    For example I counter the view that as Australia’s emissions are a small proportion of global emissions so anything we do to reduce them won’t have any effect with this analogy: “I live in a large city and I murder 10 people a year, I’ve thought about stopping, but as my city has a high murder rate it won’t make any difference.” This seems to exercise those who recommend no action considerably.

  17. 117
    Ray Ladbury says:


    Another analogy: “No raindrop thinks that it is the cause of the flood.”

  18. 118

    #116–Nice. I come across this POV quite a bit on Canadian media, too, so I’ll remember that one.

  19. 119
    Chris Dudley says:

    Caldeira’s analogy is pretty concrete when it comes to climate. Coal mining fatalities are persistent with nine so far this year in the US.

    Ending coal use to mitigate climate change could bring that number to zero now that it is pretty well demonstrated that no other method will accomplish that.

  20. 120
    Radge Havers says:

    It’s one thing to use an analogy to illuminate, but I think what we’re talking about here, in saying “argument by analogy”, is really a rhetorical sleight of hand where “reasoning by analogy” is surreptitiously palmed off on the mark. You can see the illusion if you think of the situation as comparing two patterns in such a way that it strongly suggests a given that correlation means causation. So in this sense “argument by analogy” refers to causation lite reasoning designed to amp up the emotional brain and bypass critical thought.

  21. 121
    Titus says:

    I understand ‘analogy’ is useful for linguistics. A crude communication of concepts and is not science.

    Science requires measurements, observations, mathematics and even then we only have the extent of our current knowledge and understanding to work from. E.g. we define gravity in great detail with our current knowledge but we can’t explain it.

  22. 122
    Aaron Lewis says:

    It is time for the Devil’s Advocate to stand up.

    The very worst argument by analogy began when a group of applied mathematicians said, “This atmosphere is LIKE a theoretical mathematical domain that is continuous in all directions and neighborhoods, and therefore it can be described by the differential equations of fluid dynamics or conservation of momentum..” Nothing crashed when they tried it, so they repeated the process for the oceans and the ice.

    However, chemistry tells us that the atmosphere, oceans, and ice are composed of atoms, which are separate and not continuous. And physics tells us that each atom is associated with an electric field that may be discontinuous. Therefor, no neighborhood containing real matter is continuous. The documentation supporting climate models does not offer proof that real matter always behaves like a mathematical domain that is continuous in all neighborhoods. Then, you have a singularity here, and a singularity there, and pretty soon you have a whole ocean full of singularities.

    Thus, there is an argument by analogy (e.g., climate models using the analogy of theoretical domains for real matter) that has been accepted by the IPCC and the climate science community.

  23. 123
    Edward Greisch says:

    96 NickC: “Is the whole 7% trained scientist thing a bit arrogant?”
    No. It is realistic. What we need to do is train everybody in science. Unfortunately, it isn’t going to happen. “Assuming a large proportion of non-scientists to be bereft of any skill … in weighing argument is clearly” the simple truth. But it is worse than that. IQ is a variable. If IQ were not a variable, evolution would be impossible because there would be no possibility of natural selection for intelligence. We would be no smarter than fish.

    “One can” Not “agree on the science but not the interpretation” because survival of our species is a universal value if there ever was one.

    Climate change has driven human evolution in the past. Climate change will drive human evolution again. Nature drives evolution by means of death. Mass death. It isn’t pretty or nice.

    24 Chris Dudley: No I did not say that. [edit]

  24. 124
    Meow says:

    @10 Sep 2014 @ 10:24 PM: Your argument is but to say that we don’t know how airplanes fly because fluid mechanics is bunk because we don’t simulate fluids down to the quantum-mechanical level.

  25. 125
    SecularAnimist says:

    Aaron Lewis wrote: “It is time for the Devil’s Advocate to stand up.”

    You appear to be saying that the use of mathematical models in science is in principle invalid.

    I think the Devil needs a better lawyer.

  26. 126
    Chris Dudley says:

    Arguing that intelligence is selected by evolution is a little strange when there is little evidence that it is heritable.

  27. 127
    paulina says:

    Apparently, there is a 100-page rulebook for “metaphor-wrestling.” (Article in Swedish, h/t @Douglas_Nilsson)

  28. 128
    Chris Dudley says:

    Aaron (@122),

    It is an analogy but it is a functionally useful analogy. When quantization is important, spectral line codes are used.

  29. 129
    Steve Fish says:

    Re- Comment by Chris Dudley — 11 Sep 2014 @ 1:42 PM

    The article you cite does not support your contention about the evolution of intelligence. If you don’t think that there is a genetic basis for intelligence then the difference between a chicken brain and yours is due to environment.


  30. 130
    Radge Havers says:

    CD @ ~ 126

    I’m not sure what he’s implying, but if he meant intelligence at a group level and not on an individual basis, then he’s right enough.

    However while physical scientists apparently tend to have higher IQs on average than the general population, if he’s conflating IQ with education, then he’s probably not helping his case.

  31. 131
    David Werth says:

    Mr. Smith, “denier” has been used since the 15th century to denote “one who denies”. It’s concisely descriptive of someone who denies that the Earth is warming, that it’s caused by human activities, or that it will have significant impacts on ecosystems and human societies if it’s allowed to continue. Some opinionated individuals may liken AGW deniers to Holocaust deniers, but they speak only for themselves, and no one else is obliged to adopt their interpretations.
    Comment by Mal Adapted — 6 Sep 2014 @ 4:21 PM

    Whenever I use the D word (not that often) I write “climate science denier” so it’s clear what kind of denial I’m talking about.

  32. 132
    Thomas Jordi says:

    Greenhouse effect works like a blanket? I hate that analogy. The greenhouse does, as does the blanket, hinder convection. Does CO2 hinder Convection? No. So, please, stop using that analogy. I think it’s highly flawed.

  33. 133
    Chris Dudley says:


    Evolution appears to have produced both people and chickens. So, does evolution select for birdbrains?

  34. 134
    Chris Dudley says:

    Radge (#130),

    Intelligence may simply be an emergent consequence of upright posture, for example. Perhaps selection acted on heritable skeletal properties and intelligence fell out accidentally.

    In terms of fitness, intelligence has several disadvantages, particularly helplessness during gestation and childhood. The advantage comes from how it is used to build cooperative groups to transmit knowledge. So, it could be that lack of heritability is a consequence of evolution.


  35. 135
    Meow says:

    @12 Sep 2014 @ 10:05 AM

    Evolution appears to have produced both people and chickens. So, does evolution select for birdbrains?

    Hahaha. Darwinian natural selection operates by (1) differential survival under prevailing conditions with (2) some degree of heritability of traits. However, not every trait is actively selected; some may be side-effects (“spandrels”) of a different trait that is actively selected. And spandrels themselves can be adaptive, neutral, or even deleterious. For example, sickle-cell disease (deleterious) is a spandrel of increased resistance to malaria (adaptive).

    I don’t think there is a consensus on the evolutionary path that has led to human intelligence. My pet explanation (not even a hypothesis) is that it is largely a spandrel of the development of social capabilities that facilitate cooperation (and thus survival) in small groups.

  36. 136

    “Greenhouse effect works like a blanket? I hate that analogy. The greenhouse does, as does the blanket, hinder convection. Does CO2 hinder Convection? No. So, please, stop using that analogy. I think it’s highly flawed.”

    – See more at:

    But what’s useful (even elegant) about that shopworn analogy is that, like the blanket, GHGs operate by slowing {radiative} cooling, not by back radiation causing some unphysical ‘superheating’ of the surface.

    Context is very important.

  37. 137
    Radge Havers says:


    That wasn’t addressed to me, and I assume it’s intended as a joke, but I can’t let it go.

    “All of which suggests that intelligence isn’t a matter of a handful of genes. Sure, there are some genes that, when damaged, have a catastrophic effect on cognitive abilities. But, assuming you avoid these, it seems that your intelligence is likely to be the product of a huge collection of minor genetic effects, combined with a very large helping of your environment.”

    From the arstechnica article (bold mine)

  38. 138
    SecularAnimist says:

    Chris Dudley wrote: “Evolution appears to have produced both people and chickens.”

    Make that “both humans and chickens”.

    Chickens are people too. And they are far more intelligent than most humans realize.

  39. 139
    Hank Roberts says:

    When I find myself stretching for an analogy, it’s a clue it may be time to back away from that topic. I reminded myself of that just recently after I proposed this one:

    Methane burp :: a rabid bat might be in the next room
    Fossil fuel CO2 :: a bear is chewing on your leg, right now

    Yeah, it’s hard to weight the real facts including those we don’t know, to make an apt analogy.

  40. 140
    steve Fish says:

    Re- Comment by Chris Dudley — 12 Sep 2014 @ 10:05 AM, ~#133

    Your question- “Evolution appears to have produced both people and chickens. So, does evolution select for birdbrains?” poses a non sequitur. Evolution doesn’t select for any specific outcome. It is a bunch of interacting processes that opportunistically alter living things such that they can successfully occupy some existing ecological niche. On earth, this process has resulted in bird and human brains.

    The heritability of human intelligence has been proven to near certainty. The best example is the results of the many studies of twins. What you failed to notice in the article you linked is the concluding sentence- “it seems that your intelligence is likely to be the product of a huge collection of minor genetic effects, combined with a very large helping of your environment.” So, it is specific combinations of genes that relate to intelligence upon which evolutionary processes have selected for.


  41. 141
    Chris Dudley says:


    That twins have similarities is not the same as genius begetting genius, which it does not. Breeding programs fail. That huge collection on minor genetic effects means that the outcome does not carry on from one generation to another.

  42. 142
    Edward Greisch says:

    123 myself: We need to retroactively [back a century] change the curriculum in all schools and colleges in the world to teach a lot more science. We are having a hard time getting the new STEM standards into the public schools in some states in the present time. STEM is a little bit more science, not as much as is needed.

    If I were the dictator, all high school students would be required to take 4 years of physics, 4 years of chemistry, 4 years of biology and 8 years [double classes] of math.   Probability and statistics should be included starting in the third grade.
       In college, Everybody, regardless of major, would be required to take the Engineering and Science Core Curriculum [E&SCC] plus a laboratory probability and statistics course plus more physics lab courses plus one course in computer programming.

    It isn’t going to happen.

    Most people, including people with college degrees in subjects other than science and engineering, use their emotions [emote] when they should be doing math. The human brain was ill-designed for doing science because it was designed for survival prior to the stone age. We have to do what we can with what we have.

    I had no intention of getting the discussion off-track onto evolution.

    The psychology of most people is a very strange subject. Getting them to reason as scientists do is very difficult if not impossible. Getting science students to do science is a bit easier because those who can’t, flunk out and are gone. There is a selection effect. The admissions process is also a selection effect.

    Given the people who we have to get to vote for a positive policy on GW, how do we do it? The average person thinks in ways that are a lot worse than analogy. Can we actually do any better than getting STEM passed in all 50 states? 40 states?

  43. 143

    I think this was an excellent post. I am a skeptic, but have an open mind to facts. My observation is that many (but not all) supporters of the strong AGW position have started out their comment about skeptics with comments about tobacco, big oil, the Kotch brothers, flat Earthers, uninformed, and I and other skeptics have been called denier (BTW I am Jewish). I have seen much less calling of these type names the other way. If all were as rational as you seem in this post, the back and forth would have been much less contentious. I do realize that there are bad mannered and ignorant people on both sides of the issue, but the scientists at least should follow your advice here, and should encourage their followers to also do so.

  44. 144
    Radge Havers says:

    CD @~140

    “That huge collection on minor genetic effects means that the outcome does not carry on from one generation to another.”

    WTF? Stop. Just stop. There’s no basis for that claim. You’re tap dancing, and it ain’t pretty. I suggest circling back to the topic.

  45. 145
    Radge Havers says:

    EG @ ~ 141

    “I had no intention of getting the discussion off-track onto evolution.”

    Maybe Gavin’s next article should be “On Speciousness”.

    The climate science is difficult enough as it is.

  46. 146
    Hank Roberts says:

    > That huge collection on minor genetic effects means that the
    > outcome does not carry on from one generation to another.

    Chris is right about that.
    Every child who gets a full deck has a chance at the combination that makes for genius; everyone (except identical twins) gets a shuffled and cut deck with a new arrangement of what’s inherited.

    Genetics confirmed it; it didn’t take Mendel and Darwin to figure it out. Observation made it clear: genius emerges anywhere and everywhere at all times; opportunity makes the difference thereafter.

    “… Whatever wisdom constituently is, it is like a seedless plant; it may be reared when it appears, but it cannot be voluntarily produced. There is always a sufficiency somewhere in the general mass of society for all purposes; but with respect to the parts of society, it is continually changing its place. It rises in one to-day, in another to-morrow, and has most probably visited in rotation every family of the earth, and again withdrawn.”
    Tom Paine, The Rights of Man

  47. 147
    Steve Fish says:

    Re- Comment by Chris Dudley — 13 Sep 2014 @ 12:31 AM, ~#140

    Chris, your claim that human intelligence is not heritable is not supported by the article you cited and twin studies strongly support the heritability of intelligence. If you don’t know anything about an area of science, not making strong assertions about the area shows intelligence.


  48. 148
    Meow says:

    @12 Sep 2014 @ 1:10 PM:

    …like the blanket, GHGs operate by slowing {radiative} cooling, not by back radiation causing some unphysical ‘superheating’ of the surface.

    There is no “superheating”, but GHGs absolutely do increase back-radiation. Since Kirchoff’s Law applies, the surface both emits and absorbs IR. Thus, the back-radiation from the atmospheric GHGs raises the surface’s temperature over what it would be absent the GHGs. Of course, the *net* heat flow is still from the (warmer) surface to the (cooler) atmosphere, so both quantum theory (governing radiation) and thermodynamics (governing gross statistical transfer of heat) are obeyed. See et seq for an excellent discussion of atmospheric radiation.

    I think ordinary blankets work primarily by inhibiting convection/advection.

  49. 149
    Meow says:

    @12 Sep 2014 @ 10:05 AM

    Evolution appears to have produced both people and chickens. So, does evolution select for birdbrains?

    Hahaha. Darwinian natural selection operates by (1) differential survival under prevailing conditions with (2) some degree of heritability of traits. However, not every trait is actively selected; some may be side-effects (“spandrels”) of a different trait that is actively selected. And spandrels themselves can be adaptive, neutral, or even deleterious. For example, sickle-cell disease (deleterious) is a spandrel of increased resistance to malaria (adaptive).

    I don’t think there is a consensus on the evolutionary path that has led to human intelligence. My pet explanation (not even a hypothesis) is that it is largely a spandrel of the development of social capabilities that facilitate cooperation (and thus survival) in small groups….

  50. 150
    Radge Havers says:

    Hank @ ~ 144

    Tom Payne the well known neuroscientist and evolutionary biologist? There seems to be a fear afoot that heritability somehow abrogates democracy, a bizarre notion.

    You know, among other things when this business came up, I also looked around for some pithy quotes and was struck by all the specious flights of imagination on the one hand and creationist flapdoodle on the other. And lo, as of this posting still no cites here except for a misread arstechnica summary. Not that I think this tangent should be pursued here — not sure it even belongs on the UV thread.