ارتفاع، مقایسه اجتماعی و پارانویا: مطالعه همهجانبه واقعیت مجازی تجربی

Abstract Mistrust of others may build upon perceptions of the self as vulnerable, consistent with an association of paranoia with perceived lower social rank. Height is a marker of social status and authority. Therefore we tested the effect of manipulating height, as a proxy for social rank, on paranoia. Height was manipulated within an immersive virtual reality simulation. Sixty females who reported paranoia experienced a virtual reality train ride twice: at their normal and reduced height. Paranoia and social comparison were assessed. Reducing a person's height resulted in more negative views of the self in comparison with other people and increased levels of paranoia. The increase in paranoia was fully mediated by changes in social comparison. The study provides the first demonstration that reducing height in a social situation increases the occurrence of paranoia. The findings indicate that negative social comparison is a cause of mistrust.

1. Introduction Paranoia is unfounded fear that others are trying to cause the person harm. This type of threat anticipation is hypothesised to be an extension of common feelings of vulnerability (Freeman et al., 2002). A paranoia hierarchy is conceptualised (see Fig. 1), with negative socio-evaluative concerns – the self as different and apart and hence vulnerable – underlying the experience (Freeman et al., 2005 and Bebbington et al., 2013). There is empirical evidence consistent with this view. Thoughts of vulnerability to rejection in social situations predict the occurrence of paranoia (e.g., Freeman et al., 2008); ideas about the self as a failure or weak predict the persistence of persecutory delusions (e.g., Fowler et al., 2012); and negative interpersonal self concepts have been found to be associated with paranoia (e.g., Lincoln et al., 2010). This self vulnerability perspective may partly explain why levels of paranoia are higher in patients with common emotional disorders (Varghese et al., 2011). The paranoia hierarchy.

3. Results 3.1. Demographic information The participant group had an average age of 31.5 (S.D.=13.0, minimum=18, maximum=62). The average height was 166.5 cm (S.D.=6.7, minimum=153.0, maximum=193.0). The ethnicity of the group was White (n=47), Black African (n=4), Indian (n=2), Pakistani (n=2), Chinese (n=1), other (n=4). The highest level of education reached was none/GCSE (n=4), A-level (n=23), degree (n=16), postgraduate degree (n=17). The mean score of the participant group on the Paranoid Thoughts Scale Part B was 25.6 (S.D.=11.5, minimum=17, maximum=63, 25 percentile=18.0, 50th percentile=19.5, 75th percentile=28.8). 3.2. Social comparison Scores for social comparison in the normal and lowered height conditions are shown in Table 1. It can be seen that mean scores were almost eight points lower in the reduced height condition compared to the normal height condition. This was confirmed statistically. Order of VR height presentation was a significant predictor of social comparison change scores, coefficient=−7.8 (95% confidence interval=−10.1, −5.6), standard error=1.12, t=−6.99, p<0.001. Table 1. Social comparison in VR. Height Order Mean VR social comparison S.D. Normal Normal then lowered 58.9 15.1 Lowered then normal 61.0 10.4 Total 60.0 12.9 Lowered Normal then lowered 50.6 16.8 Lowered then normal 53.7 10.7 Total 52.1 14.1 Table options 3.3. Paranoia in VR Scores for paranoia in the normal and lowered height conditions are shown in Table 2. It can be seen that mean scores on the SSPS were two points higher in the lowered height condition compared to the normal height condition. This was confirmed statistically. Order of VR height presentation was a significant predictor of paranoia change scores, coefficient=2.0 (95% confidence interval=0.4, 3.6), standard error=0.82, t=2.44, p=0.018. A selection of participant comments about the experiences is presented in Table 3. Table 2. Paranoia in VR. Height Order Mean VR paranoia S.D. Normal Normal then lowered 13.0 6.5 Lowered then normal 11.1 2.2 Total 12.1 4.9 Lowered Normal then lowered 15.5 9.6 Lowered then normal 12.6 4.8 Total 14.1 7.7 Table options Table 3. Selection of participant comments. “It felt different in the two times. I felt more vulnerable the first time [lowered condition], and also the man with the legs in the aisle was acting in a hostile way towards me the first time, but I did not feel it so much the second time, even though his legs were in the same place, I do not know why!” [Did not notice the height difference]. “I felt like people were staring more the first time [lowered condition], the second time just felt more comfortable but I do not know why.” [Did not notice the height difference]. “I felt more intimidated the first time [lowered condition], not sure why. There was a girl who kept putting her hand to her face, the man with the blue t-shirt was shaking his head at me, they were staring more at me.” [Did not notice the height difference]. “There were differences between the two times, like the people were moving differently, and there were suitcases one time but not the other.” [Did not notice the height difference]. “I noticed the second time I was shorter. People, even suitcases, were feeling high. I was frustrated to feel like a child again, felt out of place on the tube, because I was not an adult.” “Yes I noticed feeling shorter the second time. It felt more comfortable then because I was not in the line of eye sight and did not catch people’s eyes.” “Maybe I did notice a difference in my height, but I thought it was just that the headset had been put on differently so I took no notice of it.” Table options 3.4. Test of mediation The three stages for the test of mediation by social comparison of the relationship between height and paranoia are presented in Table 4. Consistent with the previous analyses, it can be seen that VR order of height presentation predicted change in social comparison scores (stage 1) and also change in paranoia scores (stage 2). However VR order of height presentation was not a significant predictor of change in paranoia scores when social comparison change scores were also entered (stage 3). The results show that social comparison fully mediates the relationship between height and paranoia. Table 4. Analysis of mediation. Coefficient Standard error t p-value 95% C.I. 1. Dependent variable: Social comparison change VR height order −7.83 1.12 −6.99 <0.001 −10.08, -5.99 2. Dependent variable: Paranoia change VR height order 2.00 0.82 2.44 0.018 0.36, 3.65 3. Dependent variable: Paranoia change Social comparison change −0.24 0.09 −2.61 0.011 −0.42, −0.06 VR height order 0.12 1.06 0.12 0.907 −2.00, 2.25