Angela Pretorius

Karma: 188

Angela Pretorius Mar 19, 2025, 7:52 PM
6 points
0
on: I changed my mind about orca intelligence
Cetaceans like orcas cannot sleep too deeply or else they will drown. They sleep half their brain at a time. Newborn orcas and dolphins don’t sleep for the first month of their life.
I suspect that cetaceans have had to dramatically lower their learning rate in order to survive on limited sleep and as a result they have only mediocre intelligence despite their huge brains.

Angela Pretorius Feb 26, 2025, 4:13 AM
1 point
0
on: what an efficient market feels from inside
Some landlords offer cheap rent but only rent to childless non-smokers who have a perfect credit score and a well-paid job (preferably a job that requires security clearance or an enhanced DBS check) and whose demographic characteristics are not too similar to those of their previous bad tenants.
Other landlords are less selective about who they rent to but charge much higher rents to compensate for the risk of property damage and rent arrears. This is why properties that are very similar in quality may be charging at wildly different rents.

Angela Pretorius Jul 7, 2023, 8:06 AM
5 points
0
on: Making Up Baby Signs
These are some of the signs that my 27 month old late-talker has invented:
-‘sit here’: taps where he wants me to sit
-‘I want a banana’: points to a picture of banana in a book, rubs his tummy then points to the fruit bowl
-‘I want to go outside’ fetches his shoes, points to his feet then runs to the door
-‘give it to me’ opens and closes hands
-‘the bin needs emptying’ runs to the kitchen bin then points to a picture of a wheelie bin
-‘please sweep up the food that I threw on the floor’ points to the dustpan and brush, then points to the food on the floor, then makes a pretend sweeping motion with his hand
Letting him make up his own gestures is much easier than attempting to teach sign language to a toddler who is too busy playing to pay any attention.

Angela Pretorius Mar 11, 2023, 1:39 PM
3 points
0
in reply to: TropicalFruit’s comment on: What do you think is wrong with rationalist culture?
That’s what the r/slatestarcodex subreddit is for.

Angela Pretorius Mar 9, 2023, 9:01 PM
3 points
0
on: The Kids are Not Okay
A few thoughts…
Have schools dropped all the fun activities so that they can spend more time catching up on the lessons missed during covid?
The teen suicide rate was declining over the 90s and early 00s. Then the No Child Left Behind act came into effect in 2003. Then the suicide rate gradually started increasing again. It is highly plausible that the no child left behind act would cause an increase in suicides, but I’m not sure why it would cause a gradual increase over many years rather than a sudden jump in suicide rates?

Angela Pretorius Feb 18, 2023, 10:25 AM
1 point
0
in reply to: Angela Pretorius’s comment on: On Cooking With Gas
Correction: Actually gas stoves are a significant source of pollution. See here https://pubs.acs.org/doi/10.1021/acs.est.1c04707

Angela Pretorius Feb 16, 2023, 11:30 AM
−1 points
on: Angela Pretorius’s Shortform
##AGI might not be conscious

###I don’t think that feedforward networks can be conscious

Integrated information theory does not allow for conscious feedforward networks.

###There is no good reason to expect AGI to be a recurrent neural network

Transformer models like GPT are basically feedforward networks [to do: check that this is correct]. Recurrent neural networks have had some successes but they are difficult to train. Whereas feedforward networks can be trained quite effectively using back-propagation. Biological neural networks are unable to implement back-propagation and instead rely on a variant of Hebbian Learning. To implement a recurrent neural network trained via Hebbian Learning on a computer wouldn’t necessarily be the best use of computational resources. AGI may very well be a feedforward network trained using back-prop.

###Anthropics All of human consciousness is about to be massively dwarfed by an enormous explosion of superintelligent, highly conscious AIs. And by some incredible co-incidence I happen to be human???

It just seems so implausible. An explosion of unconscious or minimally conscious superintelligent AIs is much more plausible.

Angela Pretorius Feb 10, 2023, 11:36 PM
3 points
0
on: Schizophrenia as a deficiency in long-range cortex-to-cortex communication
I still think that the dopamine system is involved in psychosis.

It is quite difficult for the brainstem to reward accurate perception. If dopamine production by the brainstem is in any way dependent on information that is coming in from the neocortex rather than from the brainstem’s own sensory areas then there is the potential for things to go wrong.

One part of the neocortex might get dopamine for detecting danger, and it can rewire itself to maximise its dopamine reward by hallucinating evil spirits.

Another part of the brain might get dopamine when social status increases, and it can rewire itself to maximise its dopamine reward by finding evidence that said individual is the messiah.

Another part of the brain might get dopamine whenever it comes across a really interesting hypothesis. Of course, the most interesting hypothesis is rarely the correct one.

Angela Pretorius Feb 4, 2023, 1:27 AM
2 points
in reply to: jpyykko’s comment on: [Intro to brain-like-AGI safety] 13. Symbol grounding & human social instincts
When my little one was a newborn he was just as happy being handled by strangers as he was with mum and dad. It was around four months that he started showing a preference for mum and dad and disliking strangers. I’m sure that he could recognise us long before the four month mark though.

Geese need to imprint from birth, whereas there is no immediate need for a baby who is not yet mobile to imprint on it’s parents. So if babies have an ‘imprinting window’ then it probably occurs later, after a baby has learnt to reliably recognise familiar faces in spite of changes in make-up or clothing.

Aside: Babies prefer to look at faces while still in the womb https://www.lancaster.ac.uk/news/articles/2017/babies-preference-for-faces-begins-before-birth-/.

Angela Pretorius Feb 4, 2023, 1:26 AM
1 point
in reply to: azsantosk’s comment on: [Intro to brain-like-AGI safety] 13. Symbol grounding & human social instincts
Mother geese don’t change their appearance much over their lifetime. I doubt that a chick ever needs to update its mommy thought assessor.

The ‘my kid’ thought assessor in humans is easily fooled by puppies and baby rabbits. Spend a large proportion of your waking hours around a cute animal and your brainstem assumes that it is your child.

Angela Pretorius Jan 25, 2023, 1:05 PM
1 point
on: Angela Pretorius’s Shortform
I think that psychosis can be characterised as a failure of inner alignment.

Let me explain with two examples.
1. We all seek status, but we obviously don’t have a genetically hardwired status classifier in the brainstem. Instead the rest of the brain figures out what our social status is. When something boosts our estimated status the ventral tegmental area in the brainstem sends out a dopamine reward signal. If the brain’s inner alignment mechanisms fail then the rest of the brain maximises its dopamine reward by convincing itself that it is the messiah.
2. The parts of the brain which detect threats get rewarded whenever they detect a threat so that they have an incentive to be vigilant to threats. If inner alignment fails then the threat detector circuits try to maximise their dopamine reward by hallucinating ghosts or snakes or whatever.
Many antipsychotics are dopamine antagonists. Dopamine antagonists don’t fix the underlying alignment failure but they trade off less psychosis for more apathy.

Angela Pretorius Jan 16, 2023, 11:23 AM
5 points
on: Why has nuclear power been a flop?
Brilliant article. I’m also curious about the economics side of things.

I found an article which estimates that nuclear power would be two orders of magnitude cheaper if the regulatory process were to be improved, but it doesn’t explain the calculations which led to the ‘two orders of magnitude’ claim. https://www.mackinac.org/blog/2022/nuclear-wasted-why-the-cost-of-nuclear-energy-is-misunderstood

Angela Pretorius Jan 13, 2023, 11:51 PM
2 points
0
on: On Cooking With Gas
I would have thought that toasters would cause more indoor air pollution than gas stoves? I’m not sure if this is the most accurate way to measure air pollution but toasters smell fume-y whereas gas hobs don’t.

I also wish to point out that the flame on a gas hob is blue all the time, except for the first second or two after ignition. Whereas the bunsen burners we used at school were put on a sooty yellow flame much of the time. I wonder whether chemistry teachers have an unusually high rate of asthma?

Angela Pretorius Jan 11, 2023, 7:58 PM
−1 points
−4
on: Against neutrality about creating happy lives
Aversive experiences are generally more intense than pleasant experiences. Imagine you have a choice between : a) 10 seconds of experiencing the greatest pleasure that you have ever had in your life followed by one second of the most excruciating pain that you have ever experienced or b) 11 seconds spent unconscious

I think that most people would choose option b.

Similarly, I think that most people have lives that are worth living, but there are some people with severe depression whose lives have extremely negative utility. Creating happy lives is a good thing, but I reckon that creating a life that has a 90% chance of being happy and a 10% chance of having severe depression would be a net negative in expected utility.

Angela Pretorius Jan 11, 2023, 5:53 PM
1 point
0
on: Running With a Backpack
I put a towel inside my backpack to prevent the contents from rattling. I do up the straps quite tight and if needs be I put socks around the straps so they don’t chafe against my neck. If the pocket where I keep my phone and keys is not tight enough to stop my keys from jangling then I stuff a flannel in as well. I also put hairbands around the zippers to prevent jangling noises. I also try to finish the contents of my water bottle in one go because I don’t like to have a half full bottle sploshing around.

Angela Pretorius Jan 10, 2023, 12:13 AM
−5 points
0
in reply to: gbear605’s comment on: Fiber arts, mysterious dodecahedrons, and waiting on “Eureka!”
OK, 25 is a bit ridiculous. But I still think it’s not unreasonable to believe that medieval peasants were less intelligent than, say, modern day sub-saharan Africans. Infectious diseases and malnutrition were rife, lead acetate was used to sweeten wines and foods and mercury was prescribed as a cure-all for everything from syphilus to teething.

Angela Pretorius Jan 9, 2023, 11:56 AM
1 point
−2
on: Fiber arts, mysterious dodecahedrons, and waiting on “Eureka!”
Here’s another reason why knitting may have taken so long to invent.

IQ scores in most Western countries have been rising by about 0.3 points per year over the course of the 20th century. If we assume that average IQ was stable until about 1750 when the industrial revolution began and increased by 0.3 points per year after that then the average IQ of people living before 1750 would have been about 28 by the standards of someone living in the year 1990 (I use 1990 as the benchmark because IQ scores have actually been decreasing over the past few decades).

Angela Pretorius Dec 23, 2022, 10:40 AM
1 point
0
in reply to: Richard_Kennaway’s comment on: Think wider about the root causes of progress
The Flynn effect presumably started before there were IQ tests to measure it.

Prenatal and early childhood malnutrition generally lower IQ, as does catching certain diseases in pregnancy or early childhood. Child labour might be bad for IQ too—not sure about this one though because a lot of modern schools are basically equivalent to child labour but being in school is not generally thought to lower IQ. So knocking a population out of Malthusian equilibrium would be expected to result in IQ rises.

Related: here is an essay about how the Black Death may have triggered the Rennaissance by reducing Europe’s population enough to temporarily knock everyone out of Malthusian equilibrium. https://www.nhd.org/sites/default/files/Franke_Senior_Paper.pdf

[Question] Opinions on the sleep synaptic homeostasis hypothesis?

Angela PretoriusNov 26, 2022, 7:01 PM

3 points

0 comments1 min readLW link

Angela Pretorius Oct 10, 2022, 3:57 PM
1 point
0
on: Sleep Training
Why did babies evolve to wake so frequently at night? Did frequent night waking have some evolutionary benefit to babies that outweighed the risks of sleep deprived parents?

I don’t know if there’s been much research into the long term effects of sleep training? The best information that I could find was this article https://www.bbc.com/future/article/20220322-how-sleep-training-affects-babies.

Angela Pretorius

[Question] Opinions on the sleep synap­tic home­osta­sis hy­poth­e­sis?

[Question] Opinions on the sleep synaptic homeostasis hypothesis?