We all know people who have an irrational bias against guns. Despite all the evidence they are presented with that gun owners are safe and responsible and that guns save more lives in the hands of the good guys than cause harm in the hands of criminals, they still hold on to a strong aversion.
Part of this can be caused by conditioning. A person bombarded since childhood with anti-gun messages from parents, teachers, and other role models become conditioned to thinking that guns are bad. That conditioning can be very hard for them to overcome because it has become ingrained into their psyche. These are the types of people who will recoil in horror at the mere sight of a real firearm and might even be physically unable to touch one.
Another possible cause of a strong anti-gun bias that also leads to mistrust of gun owners is psychological projection. A person might harbor hidden hostilities and anger issues that they are unable to deal with and subconsciously project those feelings onto others. When these people fervently argue that "gun toting crazies" will get into shootouts over fender benders or shoot their kid's soccer coach what they're really afraid of is that they might do such things if they had a gun. It is no different from the person who has thoughts of cheating on his or her spouse that becomes convinced the other is having an affair.
The person who recently wrote a letter to the Burlington Free Press strongly opposing the moose hunting season and suggesting that "before the next annual killing season, other residents be awarded legal permits to kill hunters..." The author may be harboring his own homicidal impulses and is projecting those unacceptable feelings onto hunters.
Some anti-gun personalities also exhibit signs of Projective Identification. This personality disorder results in personal bias affecting a person's behavior in such a way that the bias becomes a self-fulfilling prophesy. For example, a person who thinks that gun owners are overly hostile will behave towards them in a way that will elicit a belligerent response. Such a person will be rude and antagonistic to a gun owner and then take offense at their response and claim to have been threatened saying they "knew all along" that gun owners behaved poorly.
Both of these can also be exhibited in a perceptual disorder based on the tendency to perceive others as we perceive ourselves. If a person has tendencies towards aggression then they will expect that others feel that way as well. This ties back to psychological projection when a person who worries about going on a shooting spree themselves will believe that gun owners are just one bad day away from their own rampage.
These are just a few of the psychological causes that could lead to a person being biased against guns and gun owners. For such a person, no amount of logic or reasoning is likely to change their point of view and often only professional counseling can help them overcome their problems. Gun owners who come into contact with persons exhibiting symptoms of these disorders should be aware of the possibility and change their behavior accordingly to avoid further ingraining these biases into the sufferer's psyche.