In order your argument commits:

   1.  Non sequitur: failure to meet the objection.  Either give examples of double-blind experiments or demonstrate why double-blind experiments are not necessary.

No, YOU were making the demand - it's up to you to show why that method, and no others, is necessary, and why other methods are inadequate, taking into account the complexity of the subject being investigated - we're not talking about testing a specific drug for example.

   2.  Appeal to Common Practice: validity is not achieved from 'everybody doing it.'

Another unreasonable demand, it's up to you to show why a universally agreed definition is necessary - unlikely in the social sciences, and why the usual definitions offered are (supposedly) clearly inadequate.

   3.  Argument from Ignorance:  The answer is Yes.

Again you're making the accusation, and mere assertion won't do, back it up with credible examples - which serious IQ researchers say this - and are they at all typical, or an unrepresentative minority? See the conclusion to the review of Richardson below.

   4.  Argument from Authority: There are just as many, as just as good, Authorities (one cited) who object.

Mere assertion, previously I cited a major critic, Gould, but showed that he conceded some key points, and I quoted from a report by the American Psychological Society, not just one guy, and they affirmed the key points Gould conceded.

Now let's look at your (one) guy, from whom you cite no evidence or arguments. He seems to be as careless with evidence as you, and like you, he argues against straw men - cf the concluding sarcastic comment:

The Making of Intelligence
By K. Richardson. Columbia University Press, New York, 2000.

Review snippets on the cover of my copy describe this book as a "whodunnit", a "quietly passionate polemic", and a "thought-provoking view". In what follows, I can only belabor what one reads between those lines: the frustrating absence of a balanced, scholarly treatment of intelligence.
...
Opposed to any hint of genetic determinism, he has no choice but to reject computational approaches to the field. He does this by citing critiques published in 1990 or earlier; connectionism, the main approach in use today, was developed in the mid-1980s. If you see no changes in your software since 1989, he may convince you. The one exception is his citation of Geoffrey Hinton (p. 99): "As one of the leaders in the field, Geoffrey Hinton of Carnegie-Mellon University, put it in an article in 1998: `I am disappointed that we still haven't got a clue what learning algorithms the brain uses.'" Though Richardson ends his paragraph with that quotation, he is truncating Hinton, who in the source goes on to say, "but let me say one more encouraging thing"; this is followed by a lengthy, enthusiastic discussion of a promising new approach. For Richardson, because connectionists have had nearly 20 years to figure out how the brain works, and haven't, it's time to give up (p. 100). Unfortunately, all Richardson offers as an alternative is a set of metaphors based on "hypernetworks" and the conclusion that intelligence is a terribly complex emergent property. He eventually may prove to be correct, but it is a bit early to concede.

His writing is clear enough, but the treatment of sources is fuzzy beyond belief. Studies are mentioned with or without citation, and if an author is identified, the work in question may or may not show up in the short, briefly annotated chapter bibliographies. Oddly, given that a number of works don't make it to the bibliography, at least three are included in two or more. One has the impression of chapters written rapidly, perhaps out of sequence, with remembered publications cited and no effort made to track down the rest.

In sum, if you believe that "intelligence" is clearly defined, can be accurately and unambiguously measured using standard techniques, and derives from explicit, invariant mental modules that are rigidly specified by structural genes impervious to environmental effects, then read this book; it will give you a much-needed jolt. Otherwise, Gould (1996) remains definitive regarding the policy side of IQ testing, and Elman et al. (1996) provides a far better account of how complex behaviors can arise through epigenesis.

http://jhered.oxfordjournals.org/cgi/content/full/93/6/462

My statements stand.

They're not even leaning drunkenly :-)

QED.

(You see?  I can play the academic game too  ;-)

and lose :-) - and by the way - how would you know ? unless you have a universally accepted definition of "academic" and "game" ? :-)

Maybe it's because I'm a Londoner - that I moved to Nice.