We are a paranoid species. It is simply part of the human program, fixed in our hardwiring, it’s in our nature (choose your metaphor). Of course that depends upon how you define paranoia. Like most human traits, it occurs along a spectrum. Almost everyone is at least a little paranoid, and some people are consumed by overwhelming paranoia.

Paranoia is the belief that others are out to get you, that there are people or forces conspiring against your interests. It is easy to see how having a modicum of such concerns would be adaptive. Sometimes there are people (our competitors or enemies) who are conspiring against us. Keeping an eye out for such threats is healthy, it enables us to foresee  potential problems in the future and work to prevent them.  Someone unable to consider the possibility that others are working against them are considered naive. They are likely to screwed over by peers and colleagues and taken advantage of at every turn.

Excessive paranoia is counterproductive as well. Paranoid individuals may find it difficult to trust anyone or any institution. They have trouble working with others or fitting in. They waste incredible time and energy obsessing over illusory conspiracies against them. They are also likely to engage in conspiracy thinking on a broader scale, accepting, for example, conspiracy theories about 9/11, JFK, and secret government programs.

Like many personality traits, the naive to paranoid spectrum has a broad range of “healthy” and adaptive in the middle, with the extremes being progressively maladaptive – even getting to the point where it is reasonable to use the term “disorder.”

The inherent individual tendency towards paranoia is also modified by culture and situation. We learn by our experiences, so after having an experience where others actually were working against you, you are likely to be on your guard – to “become paranoid.” A soldier in Iraq may see a young man with a bulky jacket and worry they are concealing an explosive and plan to blow themselves and the soldier to pieces. This is a reasonable fear given the situation. The same thoughts would be considered paranoid by a person living in a quiet town.

In addition to the normal spectrum of human variation, there are specific brain disorders that have paranoia as a feature, most notably schizophrenia. Here it seems that there are other brain functions to consider – specifically reality testing and pattern recognition. Humans have a natural tendency to seek out patterns in the world around us. This includes patterns in events that might indicate a coordinated conspiracy. We filter apparent patterns through our reality testing hardware – does this pattern make sense, does it comport with my internal model of reality? Schizophrenics have impaired reality testing, so every pattern they think they see is extremely compelling to them.

The especially paranoid version of schizophrenia combines hyperactive pattern recognition, specifically for patterns of conspiracy, with other thought disorders, like bizarre ideation (literally bizarre ideas) and ideas of reference (thinking that everything is personal – people and events are referring specifically to them). Further the bizarre and paranoid patterns that they perceive are not inhibited by reality checking. This leads to paranoid thoughts, such as the belief that Tom Brokaw is speaking directly to them from the TV, giving them secret messages and warnings. Or that the CIA is monitoring their thoughts through the fillings in their teeth. Compelling evidence is emerging that schizophrenia is not just one end of human variation, but represents a specific brain disorder (or set of disorders).

Schizophrenia and other specific mental illnesses aside, some researchers believe that the general level of paranoia in society is increasing. British psychologist Daniel Freeman, who is a paranoia expert, for example, found that 25% of Londoners report regular paranoid thoughts. Dennis Combs, an assistant professor of psychology at the University of Texas at Tyler, found that about 10 years ago 5% of the college students that he studied had paranoid thoughts, while 15% of students today do.

The problem with this data, however, is that with any trait that varies along a spectrum, there is often no objective place to draw a line. How one operationally defines paranoia, therefore,  can drastically change the results. For this reason estimates of paranoid ideation vary from 5-50%. This variation is greater than the measured increase by specific researchers or studies. This does not mean there is not a signal in this noise – an individual researcher using the same techniques can perceive a change over time. But even mild definition creep may create the illusion of an increase.

Perhaps people are just more free to express their paranoid thoughts. There is a bit of a taboo against being too paranoid, and people are sometimes embarassed to express paranoid thoughts – especially if they are on the edge of our own reality testing. Some studies show that stress increases paranoia, so perhaps there is a real increase due to the increasing stresses of modern society. This would therefore not represent a change in basic human nature, just an increase in the situational trigger of paranoia in suscptible individuals.

Anxiety also positively correlates with paranoia.  We can therefore speculate that our current “war on terror” and constant monitoring of the threat level is increasing the general level of anxiety in the public, leading to an increase in paranoid thoughts in general. Or maybe it’s the financial collapse.

Then again, there’s always something. Today it’s the war on terror, last generation it was the cold war and the threat of nuclear anihilation.

This recent data on increasing levels of paranoia is interesting, but there are so many variables to consider I don’t think we are yet at a point where we can make any firm conclusions.  It will be an intersting line of research to follow, however.