Less Wrong is a community blog devoted to refining the art of human rationality. Please visit our About page for more information.

Comment author: somnicule 11 January 2015 03:40:15AM *  0 points [-]

My Bayes' is not very strong, so forgive me. This is about as naive as it gets.

Prior for adult ADHD is about 4%.

For working memory:

2SD difference given ADHD is 35%, and for the rest of the population it's 2.4%. I'll use LWM to represent a significantly lower working memory.

This suggests an overall population of 3.7% having a 2SD difference, since 4% x 35% + 96% x 2.4% = 3.7%

So P(ADHD | LWM) = 35% x 4% / 3.7% = 37.8%

For processing speed:

2SD difference given ADHD is 44.9%, and for the rest of the population it's 8.7%. I'll use LPS to represent a significantly lower processing speed

This suggests and overall population of 10.1% having a 2SD difference, since 44.9% x 4% + 8.7% x 96% = 10.1%

so P(ADHD | LPS) = 44.9% x 4% / 10.1% = 17.8%


Each of those increase the odds of ADHD significantly above the population baseline, and if you're experiencing ADHD symptoms in conjunction with results like that, it's probably worth seeing a psychiatrist.

Comment author: SeventhNadir 15 February 2015 12:58:36PM 0 points [-]

Thanks for taking the time to math that out :) I have seen a few psychiatrists in the past 5 years and unfortunately medication wasn't an option. I do think I'm performing better with age however!

Comment author: SeventhNadir 04 February 2014 09:24:00AM 0 points [-]

What are the prerequisites math domains someone should be proficient in if they were interested in making this career? I'm a long way off currently (just started learning calculus) and some kind of reference point would be very helpful! Congratulations by the way.

Comment author: SeventhNadir 13 February 2011 10:34:46AM *  2 points [-]

You've skipped over nicotine. While I've never smoked and could not recommend it (for many reasons) I do use nicotine patches for increased focus and productivity. Nicotine carries a lot of negative associations because of their link to cigarettes but a lot of the dangers of cigarette smoking are actually related to things other than the nicotine itself. The chemicals in a cigarette are quite toxic and cigarette smoke is harmful to the lungs. The fact that cigarettes co-administer MAOI's and have a powerful behavioural trigger that reinforces addiction makes me consider nicotine patches to probably have a low potential for addiction. On the stimulant angle, I also prefer the extended release stimulants, a slower release profile is much less spiky, and lends itself to a smoother experience, less tolerance and less anxiety.

In response to Optimal Employment
Comment author: SeventhNadir 01 February 2011 05:56:53PM *  6 points [-]

As a West Australian I think that there are certain expenses you're overlooking. You'd need access to a car, there are no buses or trains to many of the towns (sometimes the larger mining companies do organise buses or chartered flights). Internet will be slow painfully slow and prohibitively expensive, where $200 worth of hardware and $40 a month (on a one year plan) gets you a whopping 1GB of quota. Food is very expensive, alcohol even more so if you're into that sort of thing. Living in the outback can be very unpleasant depending on where you go.

My roommate is an electrician and has done plenty of fly in fly out work, while the money is (often not always) good, he can't handle more than 6 months at a time since there is often not much to do in small towns.

Honours Dissertation

3 SeventhNadir 14 December 2010 05:37AM

I'm picking a topic for my Psychology Honours dissertation next year and I've got so many options and interests that the overabundance of choice is near paralyzing. So in the interests of crowd sourcing and hopefully writing about something of substance, I'd like to hear suggestions for potential directions I could take. It can be any idea but one that frequently pops up on less wrong and needs further exploration or exposure would be ideal.

Basically feel free to offer suggestions but ideally I want something that (assuming I do it right) would help lay a part of the groundwork required to build up someones rationality.

In response to comment by [deleted] on On Lottery Tickets
Comment author: David_Gerard 29 November 2010 04:12:44PM -1 points [-]

A more realistic somewhat rational reason to buy lottery tickets would be when the gains of the lottery company are used to fund charitable projects and someone would reason that buying a lottery ticket increases the jackpot and thereby makes the lottery ticket more attractive to a lot of irrational people and thus increase the gains for the charity.

The fraction is really not very large. Camelot (the lottery operator in the UK) has in fact been specifically enjoined from stating or implying that buying a lottery ticket meaningfully contributes to charity.

Comment author: SeventhNadir 29 November 2010 04:42:55PM *  1 point [-]

LotteryWest runs the West Australian lottery and the fraction they donate to charity is enourmous, so that's a generalisation that does not necessarily hold true everywhere.

In response to On Lottery Tickets
Comment author: michaelkeenan 29 November 2010 11:08:46AM 1 point [-]

If you haven't already seen it, you might want to check out Lotteries: A Waste Of Hope by Eliezer Yudkowsky, which probably influences a lot of Less Wrong contributors on this topic.

Comment author: SeventhNadir 29 November 2010 11:40:12AM 0 points [-]

I did see it, I would have linked it in the opening sentence but I couldn't seem to make it happen with the tags.

On Lottery Tickets

-1 SeventhNadir 29 November 2010 08:21AM

I've often seen the issue of lottery tickets crop up on LessWrong and the consensus seems to be that the behaviour is irrational. It highlights for me a confusion that I've had about what it means for something to be "rational" and I'm seeking clarification. I think it might be useful to break the term down into the distinction I learnt about here, epistemic and instrumental rationality.

Epistemic rationality - This seems to be the most common failure of people who play the lottery. It might be an overt failure of probabilistic reasoning like someone believing their chances of winning to be 50-50 because they can imagine two potential outcome. Maybe they believe that they're "due" to win some money as they commit "the gamblers fallacy". Or it might be a more subtle failure resulting from correct knowledge of probability, but a fundamental inability to represent that number we call "scope insensitivity". I think in the cases where these errors are committed, no-one would argue that these people are being "rational".

However, what if someone had a perfect knowledge of the probabilities involved? If this person bought a lottery ticket would we still consider this a failure of epistemic rationality? You might say that anyone with perfect information of these probabilities would know that lottery tickets are poor financial investments, but we're not talking about instrumental rationality just yet.

Instrumental rationality - Now we're talking about it. The criteria for rationality in this case is, acting in a way that achieves your goals. If your goals in buying a lottery ticket are as one dimensional as making money, then the lottery is a (very) poor investment and I don't think anyone else would disagree. Here is where I start getting confused though, because what happens when a lottery ticket satisfies goals other than financial gain? It is conceivable that I could get more than $5's worth (here meaning my subjective and relative sense of what money is worth) of entertainment out of a $5 lottery ticket. What happens here? I hope you can see the more general problem that arises if you'd answer "It's still instrumentally irrational".

I'm not arguing that the lottery is a good idea or that it's socially desirable. I think that it does tend to drain capitol from the people that can least afford it. If you've argued the idea of the lottery to death, pick a different example, it's the underlying concept I'm trying to tease apart. I suppose it boils down to the idea that if an agent makes no instrumental or epistemic errors of rationality, and buys a lottery ticket, can that be irrational?

Comment author: SeventhNadir 18 November 2010 08:55:23AM *  4 points [-]

And I also suspect that it may apply to subgroups of people with Attention Deficit Disorder

It seems the case, the study that comes to mind is Executive Function Impairments in High IQ Adults With ADHD by Brown, Reichel & Quinlan. People with ADHD were much more likely to have Working Memory Index and Processing Speed Index (WMI & PSI) scores two standard deviations below their Verbal Comprehension Index or Perceptual Organisational Index (VCI & POI). As a side note, VCI is considered the best indicator of premorbid IQ.

I've actually been meaning to ask this for a while, can you (assuming this study is accurate) use Bayes theorem to argue that where VCI/POI>WMI/PSI is two standard deviations out, ADHD is a possibility worth considering? (and the numerical value of that possibility if I'm being ambitious?)

DOI: 10.1177/1087054708326113 for those interested.

Comment author: SeventhNadir 13 November 2010 02:10:38PM *  1 point [-]

Nice find. Some people claim that it is impossible to know the mind of god, but people clearly have ideas about what it should look like, otherwise how would they recognise it? I always imagine what would happen if "god" did exist and actually came down to Earth to introduce itself. Would the organised religions accept him? What if it started contradicting their scripture and undermining their power?

View more: Next