When awake, anxiety-producing thoughts that are difficult to repress may be replaced by behaviors, such as compulsive rituals, or physical feelings, such as abdominal cramps. Communities repress more widespread anxiety-producing thoughts and feelings with symbolic belief systems, which are similar between cultures insofar as they reflect universal fears and unique insofar as they address local concerns. More complex belief systems are sometimes called denial systems. Immortality through Religion Becker asserts that religious and cultural institutions serve in large part to deny mortality. Becker's analysis demonstrates that worldviews are heavily influenced by peoples' innate fear of death.
Repression is a psychologically adaptive response needed to manage our fears.
A serious problem, however, is that some denial systems may prompt people to harm others. For example, because religious doctrines have little empirical evidence and because they play such a critical role in fending off fears of mortality, people frequently find equally defensible competing religious doctrines very threatening. Rather than face the possibility that their own religious beliefs may be faulty, people often try to belittle, avoid, or even destroy competing doctrines. Indeed, much human misery has resulted from conflicts between adherents of different death-denying religions. Finally, many cultures appear timeless and permanent, transcending time and the deaths of individuals.