Jane McCredie: The right reason

“IT is useless to attempt to reason a man out of a thing he was never reasoned into” is a quote attributed to Irish satirist Jonathan Swift, famous for, among other things, inventing an island of tiny people somewhere off the coast of Australia.

I’ve seen variants of the quote ascribed to Mark Twain or described as a Shaker proverb, so its actual origin may be as uncertain as the location of Lilliput. Whoever said it first, it seems to hold an essential truth about the inaccessibility of our deeply held beliefs to the forces of reason.

I witnessed this recently when a work associate was lauding the benefits of a homeopathic remedy, which had apparently “cured” her infant son’s high fever. But nowhere is it more obvious than when it comes to debates around immunisation.

Andrew Wakefield, the former British doctor whose 1998 paper purporting to link the MMR (measles–mumps–rubella) vaccine to autism was eventually retracted by The Lancet, continues to champion the anti-vaccine cause from his new home in Texas with all the fire of a television evangelist.

In a new blog, hosted by the curiously named Academic Integrity Fund, Wakefield does not overly trouble himself with scientific argument, relying instead on various allegations about those who have accused him of scientific misconduct and an apparently absolute confidence in the infallibility of “maternal instinct” as an evolutionary force.

“Such instinct”, he writes, “operates in a realm and according to a set of rules that are not accessible to the physical laws of the universe”.

When maternal instinct challenges vaccination practices, many doctors find it “a pain in the ass and a bruise to the ego”, he writes.

I have no doubt that human mothers — and fathers — have evolved an instinctive knowledge of how best to care for their children, including an understanding of helpful and harmful inputs (nutritious root vegetable = good; sabre-toothed tiger = bad).

But given the slow pace of evolution, it seems a bit of a stretch to suggest we could rely on any instinctive feeling that immunising small children against measles was a threat equivalent to that of the growl of a hungry predator outside the family cave.

We may well have evolved to feel that small children should be protected from sharp objects, such as needles, and that we should avoid exposing them to unknown substances — both sensible precautions in the prescientific world. However, the challenges and choices faced by today’s parents are too complex to be dealt with by instinct alone.

Which brings us back to reason.

As reported in MJA InSight this week, the Australian Academy of Science has joined the ranks of those seeking to use the forces of reason to combat the myths and disinformation that so often cloud the immunisation debate.

In The science of immunisation, the academy spells out the risks and benefits of vaccines, debunking the alleged link between the MMR vaccine and autism along the way.

Facts in the booklet include that around three in 10 000 children receiving the MMR vaccine develop a fever high enough to cause short-lived seizures, while for children who contract measles the risk of seizure is more than 30 times greater, at around 100 children in 10 000.

A paper in The Lancet earlier this year estimated that 9.6 million deaths from measles may have been averted by vaccination over the decade from 2000 to 2010.

Those who did not come to their opposition to vaccination via reason may be immune to such numbers, but they highlight why the rest of us should never stop trying to get the immunisation message across.

Jane McCredie is a Sydney-based science and medicine writer.

Posted 3 December 2012