Thursday, November 19, 2009

Cyclone Roberta - FAKE

A public service announcement: the rumors and emails (example after the jump) doing the rounds that KwaZulu Natal is about to be hit by a "tempestuous cyclone" is fake, false, a hoax, bollocks, and completely made up. (There is a warning of heavy rainfall - "in excess of 50mm in 24 hours" - but there is no cyclone). Some observations: South Africa's east coast is very rarely hit by cyclones and email hoaxes are plentiful. Put these facts together, apply a bit of common sense, and you get doubt. And doubt should motivate some fact checking (Google is your friend)... If you did so, you'd find this East Coast Radio article saying it's fake, this cyclone tracking service showing no cyclones heading South Africa's way, and this blog entry by the SA Weather and Disaster Information Service saying it's a hoax.

Doubt will set you free.

Wednesday, November 18, 2009

Encephalon #78

The 78th edition of the mind/brain/psychology/etc. carnival Encephalon is out at Providentia. Posts to check out: Generally Thinking on the Buddhist brain, Brain Stimulant on neurorobotics, and The Neurocritic on unusual sexual changes due to various types of brain damage (including a kind of tumor-induced pedophilia).

My posts on estimating formidability from bodies and faces were featured.

Sunday, November 15, 2009

Picture: Family chain-mail fun...



Anti-vaccination and South Africa's measels outbreak

South Africa is in the grip of a measles epidemic (luckily confined primarily to the province of Gauteng), with 2000 cases and 4 deaths. The culprit? Parents not vaccinating their children (among other things) due to the fear that jabs can cause autism. Before getting into a bit more detail, I want to praise reporter Kim Hawley at the Times (of South Africa) for getting the story exactly right: her article emphasized the unscientific nature of such worries. Well done.

A press release issued by South Africa’s department of health contains the following revealing paragraph:
One striking feature of this latest outbreak is that while it has affected children of the poorer communities, it has also been concentrated among relatively well-off children, predominantly in the 15-19 year old age group. We believe that in both groups, the underlying cause has been failure by the parents or guardians to take children for immunization i.e. both the initial and follow-up doses.
It seems likely that among the well-off children (and much less so among the poorer children, where other factors were likely involved) the cause is parents’ fears over vaccines causing autism. The source of these fears is the anti-vaccination movement (and their idiotic celebrity sponsors) that has spread unscientific claims that either the MMR vaccine causes autism or that thimerosal (until recently a common vaccine ingredient) causes autism. These claims have been disproved beyond reasonable doubt. Being more influenced by Britain than America, it's probable that the MMR claim is most relevant to South Africa, so I'll focus on that. The source of the MMR-autism worry was a deeply flawed, and possibly fraudulent, 1998 study by Andrew Wakefield and colleagues, that was merely a case series of 12 subjects (that is, a series of 12 anecdotes) that could not, in principle, determine whether there was a causal link. Moreover, Wakefield had undisclosed conflicts of interest (he received £50,000 in legal aid money from lawyers preparing a case against MMR – over the years he received over £434,000 from such cases). Wakefield is also currently under investigation by the UK's General Medical Council on charges of serious misconduct, and he might lose his license to practice.

Just because the original study was flawed does not mean, of course, that the there cannot be a link between vaccines and autism. But, as I said above, numerous subsequent studies have found no such link. In other words, there is no good reason at all to think vaccines cause autism. Note to parents: VACCINATE YOUR CHILDREN. Dammit.

(via The Lay Scientist)

Friday, November 13, 2009

Lazy linking...

Your semi- quasi- pseudo- weekly dose of Lazy Linking...

"Grandma Plays Favorites"
  • A report by ScienceNOW on fascinating research on grandparent kin-altruism. According to the grandmother hypothesis, older women survive well past menopause (or have it in the first place) because over evolutionary time the marginal benefits of taking care of grandchildren were larger than the marginal benefits of additional children (possibly because the chance of having a healthy baby decreases dramatically with age).
  • Various studies have been done to test this hypothesis, but the results have been mixed. Now Fox et. al. have a proposal that could account for these mixed findings: that altruism varies by sex-linked chromosomes. In terms of the sex-chromosomes, paternal grandmothers are on average 50% related to their granddaughters, but not related to their grandsons at all. (Since a male is  XY and a female XX, a boy must get his Y chromosome from his father and his X chromosome from his mother). Maternal grandmothers, on the other hand, will on average share 25% of their sex-chromosomes with both grandsons and granddaughters.    
  • In other words, if you are a paternal grandmother it makes sense to dote on granddaughters (again, at least when it comes to sex-chromosomes) and if you are a maternal grandmother, it makes sense to dote equally. And, apparently, controlling for these different genetic interests makes sense of the previously-inconsistent data.
"Who's the Scientist?"
  • Seventh graders describe scientists before and after a visit to Fermilab. Not surprisingly, meeting an actual scientist changes children's perceptions dramatically, and for the better.
"Clever fools: Why a high IQ doesn't mean you're smart"
  • Excellent New Scientist piece on how IQ does a pretty bad job of measuring intellectual competence. The problem with people like George Bush, I have long thought (and the article basically agrees), isn't that they are stupid, it's that they subscribe to an unjustified epistemology in which they elevate intuition, ideology, and "gut feelings" over critical thinking and science. As I have said time and again, the human mind is prone to innumerable biases and rigorous thinking, humility, open mindedness and a reliance on reason are the only antidotes.
"Creationism Taught as Science in South African State Schools"
  • The title says it all. Depressing, annoying, unacceptable.  
"A Language of Smiles"
  • It has been known for a long time that the simple act of smiling can lift your mood and frowning can sour it. The most excellent Olivia Judson puts these findings together with the fact that different languages require different frequencies of mouth movements, some of which resemble smiling and others frowning. So if language A has a lot of sounds requiring speakers to pull a smile-like face, and language B lots of sounds requiring a frown-like face, we might have an interesting (but subtle and partial) explanation for different national cultures. German, for example, contains a lot of vowels that make you frown... 
 "Reforming libel law: A city named sue" (registration required).
  • The Economist argues, entirely convincingly, that England's libel laws are archaic and damaging to free speech. Some American media organizations are now actually threatening to stop publishing in England and blocking access to their websites there. 
  • Good ideas for reform include shifting the burden of proof to the claimant and capping damages. Dear House of Commons: do something, dammit. 
"Probably guilty: Bad mathematics means rough justice"
  • Innumeracy - the inability to deal competently with basic mathematics and statistics - is a Bad Thing. (As John Allen Paulos has argued). As this article explains, innumeracy in the legal system leads to miscarriages of justice.
"Next-gen PhDs fail to find Web 2.0's 'on-switch'"
  • The Times Higher Education Supplement reports on a survey that suggests 'Generation Y' graduate students have not embraced Web 2.0. C'mon guys... RSS and blogs are particularly valuable tools: use them. (I have my doubts about social bookmarking).
  • A weakness: the study (at least as reported here) did not compare patterns of use among the Ph.Ds to the wider population of Generation Y.
"Face the Facts - and End the War on Drugs" - Johann Hari
  • It so obvious I find it embarrassing to have to point it out: governance ought to be evidence-based. Alas, policymakers are notoriously immune to the facts, especially so on issues people are prone to go into moral panic about. The evidence with regards to drugs is overwhelming and clear: prohibition causes far more harm than good. Deal with it like alcoholism: decriminalize and treat it like a public health issue.
  • See also: a piece in this week's Economist on how drugs are becoming 'virtually legal' due to laws not being enforced.
"How did I get Here?"
  • Wonderful post over at Science, Reason and Critical Thinking tracing various contingent links between events, books and so on that led him to where he is now. Cue a cliche about the butterfly effect.
"Cell Size and Scale"
  • Awesome little interactive on the Learn.Genetics site showing the size of various biological parts and organisma, ranging in scale from a rice grain to a carbon atom. It reminds me of that awesome video I posted a while back on the size of the planets compared to the Sun, and the Sun compared to other stars.

Thursday, November 12, 2009

Adaptations for the visual assessment of formadibility: Part II

In Part I of this series, I summarized the experiments and findings of Aaron Sell and colleagues' paper "Human adaptations for the visual assessment of strength and fighting ability from the body and face". In Part II, I evaluate their claims.

The evidence Sell et. al. present seems compelling with regards to proposition (i): adults appear to be able to make remarkably accurate estimates of upper-body strength from even degraded cues such as static images of faces. As I noted in Part I, however, the truth of propositions (ii) (that this ability is an adaptation) and (iii) (that upper-body strength determines formidability) are more doubtful. I will assess the evidence for each of these claims, starting with the latter.

Wednesday, November 11, 2009

Skeptics' Circle #123

The 123rd incarnation of the Skeptics' Circle is out at Blue Genes. Posts to check out: The SkepVet Blog on CAM and religiosity; The Evolving Mind on cognitive biases; and Skeptic North on the lack of evidence for the healing power of prayer.

Tuesday, November 10, 2009

Skeptics in the Pub Durban

There's been a Skeptics in the Pub Joburg for a while now, so it's about time Durban got in on the action too! Our inaugural SIP is on Wednesday, November 18th from around 19:00 at Badgers in Davenport Center. (Tangent: Badger, Badger, Badger...). All are welcome! Check out the event on Facebook.

I've created a Google Map with the exact location (embedded below). Note that was recently significantly upgraded (for the upcoming Soccer World Cup), so it's now an extremely useful resource. Click on the pin on the map, and then select 'Get Directions: To Here', slap in where you are, and Google will recommend the best route. All hail Google.

View Badgers in a larger map

Just note that we might have to change the venue: if a lot more people want to come, Badgers will be too small. If we do need to change venues, it will be in the same area though (likely in Buxton's center). You'll be informed of any changes if you confirm attendance on Facebook and I'll put up any updates on my blog.

Adaptations for the visual assessment of formidability: Part I

In the last couple of years there has been an explosion in research on faces and what can be inferred from them. It turns out, for example, that you can predict electoral outcomes from rapid and unreflective facial judgments, that women can (partially) determine a man's level of interest in infants from his face alone, that the facial expression of fear enhances sensory acquisition, and much, much else. A particularly interesting addition to this literature is Aaron Sell and colleagues' paper, "Human adaptations for the visual assessment of strength and fighting ability from the body and face". Sell et. al. hypothesized that human beings possess evolved psychological mechanisms 'designed' to estimate the fighting ability (or physical formidability) of conspecifics - i.e. other Homo sapiens sapiens - from minimal visual information. An ancillary, but important, claim the authors also make is that formidability is largely a function of upper-body strength and thus the latter is a suitable proxy for the former. To summarize for clarity, Sell et. al. claim that: 
  • (i) people can estimate the formidability of others from visual cues of their bodies and faces, 
  • (ii) this ability is an adaptation, and thus evolved by natural selection, and
  • (iii) upper-body strength is the single most important determining factor of fighting ability. 
The authors’ rationale for the first two hypotheses stems from the observation that in social species such as humans, ‘the magnitude of the costs an individual can inflict on competitors largely determines its negotiating position’ (p. 575). That is, formidability is often an important component of an organism’s ability to compete in zero-sum games (notably, access to limiting resources). Given the dangers of physical confrontation, a rapid visual assessment of the formidability of an opponent could be extremely beneficial because it would allow an individual to weigh up its chances of success, and thus choose to fight only when there is a reasonable prospect of victory. Indeed, Sell et. al. note that the widespread so-called ritualized animal contests are best interpreted as joint demonstrations and assessments of formidability, with physical violence usually ensuing only when individuals are closely matched. If the ability to visually estimate a competitor’s formidability was indeed adaptive, and if violence was frequent and recurrent throughout human evolutionary history (as is likely the case), it is not unreasonable to expect natural selection to have forged mechanisms to make such estimates. Sell and his colleagues tested hypothesis (i) empirically in a number of studies and the evidence seems to bear it out overall. While the truth of (ii) is more doubtful, I will argue that, pending further research, it is reasonable to accept it preliminarily for a number of reasons. Finally, I will argue the lack of empirical evidence in the study for (iii) is problematic but not decisively so: it is clear that there is a correlation between upper-body strength and formidability, but we do not know how strong this correlation is so it is difficult to judge how good a proxy the one is for the other.

After the jump, I summarize Sell et. al.'s primary findings (though I leave out one of their experiments). In Part II - coming later in the week - I evaluate their paper.

Tuesday, November 3, 2009

African science/skepticism blogrolling for October

For those of you new to my blog, I've for a long time now been trying to foster better cooperation and communication between those dedicated to science and reason on the African continent. Part of that initiative is our carnival, another is this blogroll (which is Africa wide, though it started as South African) and the last is our mailing list on Google Groups...

So this is the updated blogroll - there are quite a few new blogs, which is a very good thing. If you know of any more, please let me know and please consider adding the blogroll to your own blog. Also, please do a post like this one linking to everyone on the list - it promotes all of our blogs.