Protection of privacy is a hot topic.  Hardly a day goes by without concerns over protection of privacy hitting the headlines with real impact (today’s example is “Google yields to privacy campaign” in setting their cookies to auto-delete.)  It seems clear that there is a general presumption in favour of privacy, in the sense that if something is seen to invade privacy this is a prima facie reason for stopping it, and the person wishing to go ahead bears the burden of justification.  But is this privacy presumption a rational response to the threat of invasive technology, or is it the result of a cognitive bias?

While I don’t work directly in the area, as a (somewhat bemused) observer I’ve always felt that there is a mismatch between the strength of feelings regarding privacy and the strength of the substantive arguments.  I think it is fair to say that in much of the debate as reported in the media no argument at all is made in favour of privacy.  It is just accepted as presumptively good.  This in itself suggests to me that there is a cognitive bias at play, even if there are ultimately good arguments for the privacy presumption. 

Moreover, while there are certainly good arguments in favour of protecting privacy in specific circumstances, I have never come across a sound policy argument that justifies a general presumption in favour of privacy of the breadth that seems to exist in the public discourse. One good policy argument in favour of privacy rights is procedural:  it helps prevent arbitrary enforcement of laws by police.  While this argument has considerable force in some contexts, it doesn’t explain the breadth of the privacy presumption:  Google puts cookies on everyone’s computer.  More generally, privacy concerns are just as prevalent in commercial and individual contexts where arbitrary law enforcement just isn’t at issue.  Another common position is the ‘bad laws’ argument – marijuana / surfing porn / speeding (pick a pecadillo) really isn’t that bad, and the presumption of privacy reduces enforcement of these bad laws.  The easy response to this is that the presumption of privacy also reduces enforcement of good laws, and most laws are good laws so the presumption must be a net negative with respect to law enforcement.  Of course, this isn’t an exhaustive analysis of the substantive arguments for privacy rights.  But the thinness of the arguments that are most often raised in favour of privacy inclines me to look for an explanation of the privacy presumption based on cognitive biases.            

I can think of two types of cognitive bias that might lead to the privacy presumption.  First is simply the salience bias.  We’ve all done something wrong that we would like to keep hidden (well, not me, but most people), and the consequences to us of being caught are far more vivid and easily imagined than are the indirect consequences of better enforcement against everyone else.  This is essentially the bad laws argument with a psychological twist.

A second possibility is that we might have evolved a direct cognitive bias in favour of privacy.  Suppose that free flow of information is in fact that the best social policy.  This would set up a classic prisoners’ dilemma:  the best case overall is if no one keeps information private, but the best case for me is that I keep my information private and everyone else reveals theirs.  Since everyone has the same reasoning, everyone elects to keep their information private, even though free flow of information would be substantively desirable.  Private information was no doubt as valuable in the ancestral environment (where is the bees’ hive, who am I having an affair with) as it is today, and a cognitive bias in favour of privacy might have evolved in response.

Of the two cognitive arguments I like the second one best, but that could just be because it’s more interesting than a plain old salience argument.  In any event, I find the cognitive arguments much more persuasive as an explanation of the general privacy presumption than are the substantive arguments.  Are there good general substantive arguments that have I missed?  Is there a cognitive bias in favour of privacy?  Are there other good cognitive arguments that would explain the privacy presumption?