Overgeneralisation
Overgeneralisation is taking a single negative event and turning it into a sweeping general rule, without ever actually testing whether that rule holds true. Words like 'always,' 'never,' and 'everybody' tend to run through this kind of thinking, extending one specific disappointment into a supposed pattern covering all of life.
Illustration
After a single unreturned phone call from a friend, a man concludes that 'nobody ever wants to talk to him' and stops trying to reach out to anyone else for weeks, treating one instance as though it proved a permanent truth about all of his relationships.
References
- Casey, P. & Kelly, B. (2019). Fish's Clinical Psychopathology, 4th ed. Appendix II, 'Defences and Distortions'.