Kennedy argues that collective beliefs tend to change more slowly than individual opinions. Ideas embedded across a society are reinforced by habit, institutions, shared experience and prevailing assumptions, making gradual changes in circumstances less likely to produce an immediate shift in public attitudes. A nation may therefore continue to interpret new problems through established ways of thinking even as conditions change.

In Why England Slept, Kennedy applies this observation to Britain’s response to the growing threat from Nazi Germany during the 1930s. He suggests that major shocks were needed before established attitudes towards defence and rearmament changed decisively. The wider point is that crises can act as catalysts for collective change by making previously abstract or contested dangers appear immediate. The quotation describes this as a feature of national psychology rather than as a judgement about any particular society’s intelligence or character.