People who are prone to "mistrustful thoughts" are more prone to feelings of inferiority when viewing a social situation from a "lower height."

"Being tall is associated with greater career and relationship success. Height is taken to convey authority, and we feel taller when we feel more powerful. It is little wonder then that men and women tend to over-report their height," Professor Freeman, an MRC Senior Clinical Fellow in Oxford's Department of Psychiatry said in an Oxford University news release.

The researchers used a virtual reality simulation of an underground train ride to make their findings. They noticed that making a person's height lower could lower their self-esteem and make them more likely to feel as if others are out to get them. The goal of the study was to move towards a "more effective psychological treatment for severe paranoia."

A research team looked at 60 women who were prone to "mistrustful thoughts." The study participants went through the same train "journey" twice; in one scenario their character was about a head shorter than the other experience.

Most participants did not notice the height difference, but reported more instances of social inferiority (such as feelings of being "incompetent, unlikeable, and inferior") when they perceived the scene at a lower height. These feelings led to an "increase in paranoia towards other passengers.

"This all happened in a virtual reality simulation but we know that people behave in virtual reality as they do in real life," Freeman said. "It provides a key insight into paranoia, showing that people's excessive mistrust of others directly builds upon their own negative feelings about themselves."

"The important treatment implication for severe paranoia that we can take from this study is that if we help people to feel more self-confident then they will be less mistrustful. This prediction is exactly what we are testing in the next phase of our work, a new [randomized] controlled clinical trial," Freeman said.