Cognition and perception

Are we all paranoid?

Lyn Ellett and Tim Wildschut consider evidence of paranoia in non-clinical populations

11 May 2014

In June 2013 Edward Snowden, a US intelligence analyst, shared classified information on a variety of top-secret US National Security Agency (NSA) programmes, the details of which were published in The Guardian and Washington Post newspapers. This included the interception of US telephone metadata and details of the PRISM surveillance programme, which allegedly allows the NSA to access e-mail, web searches and other internet traffic in real time. We also know now that the UK’s Tempora programme records huge amounts of personal data, including e-mails, social networking activities, internet histories and telephone calls.

In the wake of the scandal in the US surrounding the NSA’s PRISM surveillance programme, it is possible that users may come to distrust the internet for communication, sharing and storage – because individuals might now fear that the government will be spying on them, whether or not they are the object of that surveillance.

The psychology of surveillance

The psychological effects of surveillance are well known. We know that surveillance has the potential to impact on both mental health and performance. For example, research has shown that surveillance can result in increases in anxiety, fatigue and stress. At work, it can reduce performance and impact on our sense of control. In addition, we also know that surveillance promotes distrust between the public and the state, it breeds conformity and can undermine the influence of authority. Interestingly, surveillance is also consistent with a key theme in paranoia – thinking that other people are spying on us, watching us, are out to get us or harm us in some way. Indeed, in clinical paranoia, it is very common for themes involving surveillance and electronic devices, particularly computers, to be part of paranoid ideation. But is there any evidence that paranoia exists in the nonclinical population?
Is paranoia common in the general population?

Paranoia is a perception of malevolent intent from another person or group and has been described as ‘the 21st-century fear’ (Freeman & Freeman, 2008). In recent years, there have been a large number of studies showing that paranoia is a common and distressing experience in the nonclinical population. For example, a recent large-scale survey showed that paranoia occurred in around one third of the general population (Freeman et al., 2011), and studies have also examined idiosyncratic experiences where individuals describe a personal experience of paranoia, which is assessed across key cognitive, behavioural and affective dimensions (Ellett et al., 2003). This has triggered a conceptual shift towards viewing clinical paranoia as continuous with experiences of the healthy population. Nonclinical paranoia is thus a phenomenon of interest in its own right, as well as in its potential capacity to inform the understanding and treatment of clinical paranoia.

Although research to date has found evidence of paranoia in the nonclinical population, and much research has examined factors that are implicated in the transition to clinical psychosis, the vast majority of individuals reporting nonclinical paranoid experiences do not  go on to develop any form of clinical psychopathology. This poses an interesting question – what is it that keeps individuals in the nonclinical domain? Recent research has suggested that unlike the clinical counterpart, nonclinical paranoid beliefs might change naturally over time. For example, in one study, participants were asked to describe a paranoid experience and whether their beliefs about this experience had changed. The results showed that 37 per cent of participants reported a change in their beliefs about a specific paranoid experience (Ellett et al., 2003). Another study examined reasons individuals themselves gave for change (Allen-Crooks & Ellett, 2014) and found that the paranoid event came to be seen as likely to happen to anyone – part of normal social interactions. Indeed, working to ease a tendency to interpret events as occurring because of something about oneself has long been a key process in cognitive behavioural therapy. Individuals also reported that over time, they were more able to accept and let go of paranoid experiences, which is consistent with a growing body of evidence for mindfulness-based approaches for distressing psychosis (Chadwick, 2006).

Can paranoia be manipulated?
More recently, there has been a focus on developing and validating experimental paradigms to study paranoia. The first paradigm involves participants undertaking an experimental task with pre-set outcomes, in which they either receive ambiguous or failure feedback. Participants complete the task under conditions of high or low self-awareness, which is manipulated via the presence or absence of a camera. Interestingly, state paranoia can be triggered by the combination of high self-awareness and either ambiguous feedback or explicit failure (Ellett & Chadwick, 2007). Furthermore, if one accesses positive
self-representations, or has the opportunity to affirm one’s values (Kingston & Ellett, 2014), the impact of these environmental conditions on the occurrence of paranoid cognitions is significantly reduced. This indicates that high state self-esteem might reduce one’s susceptibility to becoming paranoid.

A second experimental paradigm for studying paranoia involves the use of virtual-reality environments (e.g. Freeman et al, 2008). Participants explore a virtual environment, which contains computer characters, known as ‘avatars’, who are pre-programmed to behave neutrally. Several studies have now shown that state paranoia can in fact be triggered in these neutral virtual environments. This is an important finding because it demonstrates that paranoia can be triggered in environments that lack an objective threat. Indeed, this is a key strength of this paradigm as it allows the researcher to control the environment, and thus be certain that any paranoia detected is unfounded. The paradigm can also be used to assess individuals’ in-the-moment (rather than retrospective) attributions for events.

Other experimental paradigms have also been used to examine some of the key characteristics of paranoia. For example, the prisoner’s dilemma game (PDG) has recently been validated as a paradigm for the study of paranoia in the general population (Ellett et al., 2013). The PDG involves two players who make a simple forced choice to either cooperate with, or compete against, each other. The PDG captures several key defining characteristics of paranoia – it is interpersonal as it involves at least two players, it concerns threat and perceptions of others’ intentions towards the self, and it is necessarily ambiguous (a player is not aware of their opponent’s choice at the time of making their own choice). As we have already seen, ambiguity is a known trigger of nonclinical paranoia (Ellett & Chadwick, 2007).

Using this paradigm, we predicted, and found, that state paranoia was associated with the choice to compete on the PDG – the rationale being that people experiencing paranoia about their opponent’s intentions in the PDG would be more likely to compete, as competition provides the best defensive strategy against a presumed malevolent other. Because paranoia is inherently interpersonal, and therefore should be assessed within an interpersonal context, we tested this by varying whether individuals interacted in the PDG with either another person or a computer. We predicted, and found, that paranoia was again associated with the choice to compete in the PDG, but only when playing against another person, and not when playing against a computer. Finally, we examined motivations for competing in the PDG. A player might choose to compete either due to greed (i.e. predicting that the opponent will choose to cooperate and responding exploitatively to this possibility) or distrust (i.e. predicting that an opponent will compete and responding defensively to this possibility). It is important to distinguish between these two motivations because nonclinical paranoia should only be reflected in distrust-based (and not greed-based) competition – only distrust-based competition flows from the perception that the opponent possesses malevolent intentions towards the self. We found that both state and trait paranoia were associated with distrust-based (but not greed-based) competition. Distrust-based competition in the PDG therefore provides a behavioural signature or marker of nonclinical paranoia.

Why so common?
It is important to ask why paranoia might be so common in the general population. One possible explanation is that paranoia is a trait that was selected and distributed in humans due to its adaptive value (Ellett & Chadwick, 2003, 2007).

Whilst there is a risk that any human behaviour or trait that is reasonably common will be inferred to be necessarily adaptive, paranoia is a promising trait to consider from an evolutionary perspective. Paranoia is first and foremost a perception of interpersonal threat to self – this is clearly an ecologically important problem, which is one of the key issues in evolutionary psychology when considering why a trait might undergo natural selection (Sedikides & Skowronski, 1997). Indeed, detecting threat in everyday social situations is important. For example, in real-life social situations we may need to be viewing something of central interest, whilst simultaneously being able to monitor the changing social scenery around us. For example, imagine that you are walking down a crowded shopping street, and are surrounded by other people. The ability to detect where another person is looking is socially important, both for determining their intentions towards us and in signalling relevant stimuli in the environment. This is important as it allows us to detect potentially threatening or hostile people.

In evolutionary terms, a false positive (fearing harmless people) is potentially less costly than a false negative (failing to fear others who are truly hostile and therefore pose a genuine threat) (Haselton & Nettle, 2006). There is a clear adaptive value in remaining vigilant once a threat has been detected, and the evolutionary maxim, ‘better safe than sorry’, could thus explain why paranoia might persist in nonclinical populations.

The focus on paranoia as a social phenomenon that is common in the population at large has widespread significance, and has the potential to relocate paranoia within the rich human repertoire of daily interpersonal behaviour, where we strongly believe it belongs. It can be measured reliably using self-report questionnaires, and more recently, the focus has been on the development and validation of experimental paradigms. This has been a significant development, not only in terms of identifying factors that trigger paranoia, but also in learning about what might buffer or attenuate nonclinical paranoid experiences. Studying paranoia in the general population is important, not just to help us understand clinical paranoia, but also in terms of elucidating factors that help people to stay in the nonclinical domain, and avoid the transition to clinical psychosis.

Lyn Ellett
is in the Department of Psychology, Royal Holloway University of London
[email protected]

Tim Wildschut
is in the Department of Psychology, University of Southampton
[email protected]


Allen-Crooks, R. & Ellett, L. (2014). Naturalistic change in nonclinical paranoid experiences. Behavioural and Cognitive Psychotherapy.
Chadwick, P.D.J. (2006). Person-based cognitive therapy for distressing psychosis. Chichester: Wiley.
Ellett, L., Allen-Crooks, R., Stevens, A. et al. (2013). A paradigm for the study of paranoia in the general population; The prisoner’s dilemma game. Cognition and Emotion, 27, 53–62.
Ellett, L. & Chadwick, P. (2007). Paranoid cognitions, failure, and focus of attention in college students. Cognition and Emotion, 21, 558–576.
Ellett, L., Lopes, B. & Chadwick, P. (2003). Paranoia in a non-clinical population of college students. Journal of Nervous and Mental Disease, 191, 425-430.
Freeman, D. & Freeman, J. (2008). Paranoia: The 21st century fear. Oxford: Oxford University Press.
Freeman, D., McManus, S., Brugha, T. et al. (2011). Concomitants of paranoia in the general population. Psychological Medicine, 41, 923–936.
Freeman, D., Pugh, K., Antley, A. et al. (2008). Virtual reality study of paranoid thinking in the general population. British Journal of Psychiatry, 192(4), 258–263.
Haselton, M.G. & Nettle, D. (2006). The paranoid optimist: An integrative evolutionary model of cognitive biases. Personality and Social Psychology Review, 10, 47–66.
Kingston, J.L. & Ellett, L. (2014). Self-awareness and nonclinical paranoia. Manuscript submitted for publication.
Sedikides, C. & Skowronski, J.J. (1997). The symbolic self in evolutionary context. Personality and Social Psychology Review, 1, 80–102.