Comment author: Jonathan_Graehl 21 November 2009 05:46:05AM 2 points [-]

While alcohol does in fact reduce doubt and insecurity, I wouldn't jump to: any crude global brain impairment is likely to first impair self-doubt/monitoring.

Otherwise, nice pep talk.

Comment author: Annoyance 21 November 2009 08:42:30PM -1 points [-]

Alcohol is an just example. It's well-known that crude global brain impairment reduces self-monitoring first.

Comment author: Cyan 20 November 2009 07:50:16PM *  3 points [-]

You need to be a little more careful about such absolute statements. The definition of factorial(.) as

factorial(n) = n*factorial(n-1)

factorial(0) = 1

references itself and is valid.

In response to comment by Cyan on The Featherless Biped
Comment author: Annoyance 20 November 2009 08:11:36PM -2 points [-]

Recursive definitions are possible, but they must still be founded on a base level that does not reference itself. Each other level can then be defined in a way that is not self-referential.

Comment author: DanArmak 31 October 2009 02:06:53PM *  3 points [-]

The definition of a mammal is simple: descent from the most recent common ancestor of all mammals. In practice, to avoid circularity, it is sufficient to take the MRCA of a few indisputable mammalian groups such as primates, rodents, carnivorans, ungulates, etc. to include all mammals.

This definition is useful because it turns out that there are many traits unique to mammals, and any given mammal will have almost all these traits. Many such traits are anatomical/biochemical/etc. (Many outwards traits like live birth or so-called "warm blood" aren't unique to mammals.)

However, even if this definition wasn't useful to us, the group Mammalia would still exist. It's a natural evolutionary group (clade) in phylogenetics, to which we merely give a name. (Edit: and cladistics is a natural way of classifying species (among other ways). By natural I mean a classification that tends to match common and unique traits of species in the same clade, and which is causally linked to the history of of the species and to predictions for their future, so that I would expect aliens to have a relatively high probability of using similar classifications.)

The precise clade referred to by the word Mammalia can change depending on context. It makes sense to ask whether borderline species like platypuses are mammals or a sister group of mammals. That's the fuzzy nature of any classification of real things. But the natural limits of the category "mammals" lie somewhere around the monotremes. A group which doesn't include dolphins is definitely not the group of all mammals.

Comment author: Annoyance 20 November 2009 07:28:17PM -5 points [-]

"The definition of a mammal is simple: descent from the most recent common ancestor of all mammals."

Valid definitions cannot reference themselves.

Comment author: Technologos 08 September 2009 04:23:39PM -1 points [-]

If a fuzzy definition becomes a massive problem, then that definition clearly wasn't in existence merely to simplify speech.

Regarding mammals, is there a use for the term that requires its inclusion of dolphins? Does the existence of sweat glands usefully separate mammals from other animals? After all, mammals in general share a variety of properties: most give live birth, most have hair, most are warm-blooded, etc.--but we admit to the category of mammals many animals that fail one or more of these criteria.

A well-defined but useless category (I am not arguing that "mammal" is such a category, as there may well be a biological use for it) may be pedagogically interesting but otherwise may merely confuse our understanding of thingspace.

Comment author: Annoyance 31 October 2009 01:51:52PM -2 points [-]

".--but we admit to the category of mammals many animals that fail one or more of these criteria."

No, we don't. Dolphins have all of the required attributes to be considered mammals. If they didn't, we couldn't call them mammals any longer.

Comment author: komponisto 23 October 2009 08:51:41PM *  5 points [-]

Which weighs more: a pound of feathers, or a pound of gold?

[...rationality discussion...]

I must be missing something. I thought the point of this riddle was the difference between avoirdupois and Troy weight -- a simple matter of (rather esoteric) factual knowledge not contained in the structure of the question.

Comment author: Annoyance 24 October 2009 04:19:28PM 0 points [-]

That is an absolutely charming interpretation, and one that makes a lot of sense. However, in my experience, it's not how the riddle is commonly used.

That would be a great way to show off your knowledge of jeweler's weights, though.

Comment author: Psychohistorian 23 October 2009 06:43:14PM 5 points [-]

Questions about a property rarely contain their own answers in a trivial way

I think this fact may explain most of the reaction; the answer is slipped into the question with a couple words that don't interrupt the flow. The questions is pointless, but we don't expect questions to be pointless, so we don't really hear it right or interpret it correctly, and we answer the question that would actually make sense.

Comment author: Annoyance 23 October 2009 07:51:04PM 0 points [-]

There's more to it, of course. Ask the question with substances that don't produce strong associations regarding "weight" (really, density), and people tend not to get it wrong no matter how much time pressure is involved.

Comment author: Technologos 05 September 2009 06:05:48AM 1 point [-]

At what point do we say that the problem lies in the definition of a category? Since ordinary people have no especial use for the category "bird," it's unsurprising that they haven't nailed down characteristics that would allow such a use.

Categories that we need--that must reliably possess some characteristic(s) such that they are useful--tend to have strict necessary and sufficient conditions for inclusion. Categories that we use purely to simplify speech can get away with fuzzier definitions.

Is the dolphin really a fish? That depends: is that thing over there really a blegg?

Comment author: Annoyance 08 September 2009 01:22:39PM -1 points [-]

The biological category of 'mammal' is quite well-defined, thank you.

And fuzzy definitions are fine until you're dealing with a case that lies in the penumbra, at which time it becomes a massive problem.

Comment author: RichardKennaway 04 September 2009 09:17:09PM 1 point [-]

No, it's not. Associational processing can emulate logical thinking, but it's not restricted to it and will not normally produce it. Restrictions have to be added for logic to arise out of the sea of associations.

In other words, we have to learn logic, we're not born with it. This is news?

Electric charge doesn't spontaneously do arithmetic either.

Comment author: Annoyance 08 September 2009 01:21:31PM -6 points [-]

In other words, we have to learn logic, we're not born with it.

No.

Electric charge doesn't spontaneously do arithmetic either.

No. It does nothing but mathematics.

Comment author: Annoyance 08 September 2009 01:18:04PM 0 points [-]

This looks sincere to me, and given that it's sincere, people really ought to be allowed more chance than this to recover from their mistakes.

I say that depends entirely on the nature of the mistake. Gross negligence should not be forgiven, although the proper response is not necessarily retributive.

Comment author: Jack 03 September 2009 12:14:49AM 5 points [-]

The fact that you felt the need to compare the points you made with knowing the composition of water just demonstrates the need for citations. If these points about psychology were actually as commonly known as the composition of water then you wouldn't need an analogy- you would just sarcastically remark "A citation? Really?".

Maybe if psychology was required in high school and earlier the way chemistry is we would all know this already. As it stands, at least 3-4 of us didn't realize that these points are widely known and non-controversial (and have taken the time to say so) so I think there is good reason to think that these points aren't known by non-psychologists the way certain chemical compositions are by non-chemists.

In response to comment by Jack on The Featherless Biped
Comment author: Annoyance 04 September 2009 08:03:35PM -6 points [-]

If these points about psychology were actually as commonly known as the composition of water then you wouldn't need an analogy- you would just sarcastically remark "A citation? Really?".

Nope, 'cause you people know virtually nothing about psychology. Which is why I so frequently see statements of boggling ignorance made here about how and why human minds do stuff.

If a person wants citations to support a statement about the composition of water, my reaction is to tell them to go find a schoolchild and ask them about chemistry. Or pick up a brightly-colored children's book about science and learn something. Maybe watch a little 3-2-1 Contact or Bill Nye.

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