This research is by no means new, but the ripple effect of the original study is still salient - even more than 10 years later. For those of you who do not know, the original study found a correlation between children who had been administered the MMR vaccine (measles, mumps, rubella) and autism. Immediately, vaccination rates dropped drastically in the UK and this silliness eventually infected its way to the US. It is worth mentioning that the original study had a sample size of 12. That's it, just 12 - 11 boys and 1 girl. That doesn't seem very balanced, especially since the prevalence rate for autism in boys is up to 4 times higher than in girls. The reason the news spread so quickly was because of the media and its penchant for over-dramatizing and misrepresenting scientific findings in order to sell newspapers.
Autism Spectrum Disorder (ASD) is a relatively newly identified phenomenon as Penn and Teller rightfully point out. Individuals with ASD in the past would have been labeled as weird, the clever kid, the socially awkward computer geek among others. Now that we have the ability to diagnose - albeit with a lack of specificity hence the spectrum in ASD - the amount of individuals diagnosed has risen. So of course, since more children are getting vaccinated and more parents want to protect their children against diseases there is an increase in both and an illusory correlation can be made. That doesn't mean that they are linked. As I'm sure you've heard a million times before, correlation ≠ causation, and it never will.
One of the hilarious things in last night's episode of Penn and Teller's Bullshit was Jenny McCarthy's role in the anti-vaccination movement. Apparently she had a child with autism who was cured - there is no cure for autism - and now she parades around the US campaigning against vaccinations. What an upstanding citizen, preaching as if an expert on a subject she knows little about, preventing parents from protecting their children from diseases because her child was misdiagnosed as having ASD. Misunderstanding science can be detrimental to society, luckily for you the IB won't release you from its clutches until you understand the fundamentals of science. Consider it a vaccination against ignorance.