All types of pattern recognition systems suffer from two types of errors, there is the type 1 error, the false positive, and there is the type 2 error, the false negative.

HADD is a type 1 error, of seeing something that isn’t there. There is a trade-off between these two types of errors, you can have zero type 1 errors if you reject every instance, but then your type 2 error rate is maximized. You can have a zero type 2 error rate if you accept every instance but then the false positive rate is maximized.

There is a deal of pattern recognition in all forms of communication. The bit count of the data stream is insufficient to convey the information content of language without enormous data compression and decompression at the other end. That decompression is pattern recognition. When the compression and decompression are done seamlessly and with little loss in data, there is good communication with no misunderstanding. When the data compression and decompression do not happen seamlessly, then there is data loss, and the message can be garbled or misunderstood.

Usually the data compression and decompression happens seamlessly and is transparent to the users, they are not aware that it is happening. They become aware when it does not happen seamlessly, when the error rate goes up, there is miscommunication, and then there are default responses.

I think one of the default responses to a high error rate in communication, and particularly in non-verbal communication is the triggering of xenophobia. It may not always be that simple, but that may be an important component.

http://daedalus2u.blogspot.com/2010/03/physiology-behind-xenophobia.html

Psychoogists and neuroscientists in recent years have demonstrated that our brains are hardwired to distinguish things in our environment that are alive from those that are not alive. But “being alive” (from a psychological point of view) is not about biology, but agency – something that can act in the world, that has its own will and can cause things to happen. Sure, this is a property of living things, but that’s not how our brain sort things out. We can perceive agency in non-living things if they are acting as if they are agents.

This is reflected even in our visual system, which separates out visual information into different streams according to the type of information. One division is between information about actions and information about objects. The object stream is also divided into brain regions that deal with inanimate objects and other regions that deal with living things or animate objects. So on a fundamental level our brains treat agents different than objects – from the moment we see them.

Bruce Hood, author of Supersense, goes over in his book the psychological studies that have documented and described the human tendency to think of objects differently than agents. We imbue agents with an essence – a unique living force, even while infants. Objects are just generic things, totally interchangeable. While agents have their own unique essence. Interestingly, children can come to view a favorite toy (a stuffed animal, for example) with the properties of an agent and will treat it like a living thing. This reinforces the notion that the distinction we make is not between living and non-living so much as agent vs object. This likely also explains why we can watch a cartoon and react emotionally to the characters as if they were real – they are not living, but we see them as agents.

According to Barrett, HADD works in part by detecting any movement that is non-inertial – something which seems to be moving of its own volition. We then assume it is acting with agency and react accordingly. This likely provided an evolutionary advantage – it is better to assume the rustling in the bushes was not the wind but a hungry tiger. So we are descended from hominids who were more paranoid and had hyperactive agency detection, because they were less likely to be eaten by predators.

Paranoia is not a biological advantage.

It causes irrational reactions
to non-threatening situations wasting energy and placing undue stress

and produces inappropriate and faulty strategic and tactical thought and maneuvers.

Screwed up strategic and tactical actions placed early biologically susceptible hominids in harms way.

It is not paranoia if something really IS trying to get me!

However, I do not think that paranoia is advantageous...
(in general)

the term paranoia is not quantifiable, at least in any way I can understand.
....

So how does one determine what is actually paranoia, and what is just normal concern?

The way I was using the term in this convo, those are two regions of the same spectrum - the spectrum of inclination to respond to a possible threat. Clearly, there is often an evolutionary advantage to not waiting until a threat is proven real before responding.

So how does one determine what is actually paranoia, and what is just normal concern?