Saturday, 7 September 2013

Living on the Edge - Confirmation Bias

The book "Living on the Edge" by Jonathan Burke is due to be published in November 2013, but excerpts from the book are being published at the Facebook page. I'll be mirroring them here. 

Confirmation bias

‘It is more common to reject or ignore arguments when we disagree with the conclusion than when we agree with it. Psychologists have studied and documented this human tendency, which they refer to as confirmation bias.’[1]

Put simply, confirmation bias is our natural tendency to look for information which confirms what we already believe, and ignore or reject information which disagrees with or conflicts with our beliefs. When choosing between two sources of information, we tend to place greater confidence and value in the source which confirms what we already believe.

The 17th century philosopher Francis Bacon described this tendency in his book ‘The Advancement and Proficience of Learning Divine and Human’ (1605), noting that people are more strongly influenced by information which confirms (or affirms), their beliefs, than information which contradicts (or negates), them.

‘Besides, even in the absence of that eagerness and want of thought (which we have mentioned), it is the peculiar and perpetual error of the human understanding to be more moved and excited by affirmatives than negatives, whereas it ought duly and regularly to be imnpartial; nay, in establishing any true axion the negative instance is the most powerful.’[2]

This is a dangerous tendency because it erodes our capacity to think critically, and to examine our own beliefs for error. One way to help guard against it is to seek out arguments by those who disagree with our position, reading their criticism and counter arguments.

Another way is to present our case to readers who are neutral or even biased against our case, to see how it withstands criticism by those who can look at it without our personal bias. This is a key strength of the peer review process.

[1] Govier, ‘A Practical Study of Argument’, p. 106 (2009).

[2] Bacon, ‘Advancement of Learning’, in Creighton (ed.), ‘Advancement of Learning and Novum Organum’, p. 321 (rev. ed. 1900).