Paranoid (persecutory) delusions are the most common symptom of psychosis and, arguably, ubiquitous in the earliest stages of illness. There is now compelling evidence that these delusions exist on a continuum with subclinical paranoia as experienced at times by most ordinary people. A generation of psychological models (e.g. Bentall et al. 2011; Freeman, 2016) have converged on the idea that cognitive biases coupled to low self-esteem make important contributions to these experiences, and have had some succes in guiding the development of psychological interventions. However, these models have some limitations: (i) they do not articulate how delusions are different from other kinds of firmly held beliefs (eg. political ideologies); (ii) they are not rooted within a developmental framework; (iii) they emphasize the role of explicit cognitive processes but we now know that implicit (associative) processes play an important role in human cognition. This update will include new data: (i) a network analysis of paranoia in relation to other kinds of beliefs and attitudes (political beliefs, conspiracy theories); (ii) findings on the role of attachment in paranoia and on the relationship between social identity (the sense of belonging) and paranoid beliefs; (iii) preliminary findings on how theory of mind deficits moderate the pathway from insecure attachment, making the difference between paranoia and ordinary mistrust. The overall picture should be regarded as an evolution of earlier models, in which paranoia is considered to be a product of the failure to satisfy the human need to belong.