" The slogan was ‘Don’t trust anyone over thirty’. Sixty years later the slogan became, ‘Don’t trust anyone over ninety’. "
- John McCarthy

In the context of the quote, the speaker is reflecting on a change in societal attitudes over time. The phrase "Don't trust anyone over thirty" suggests a sentiment popular among young people who believe that those older than them are out of touch or no longer credible due to their age and experiences. Sixty years later, this idea has evolved to "Don't trust anyone over ninety," implying that the original demographic now holds positions typically reserved for the elderly in earlier generations.

At its core, the quote delves into generational attitudes towards authority and the erosion of trust as people age. It highlights how societal norms shift dramatically across different eras, often with a critique on traditional hierarchies and the perceived wisdom or credibility that comes with seniority. The evolution of distrust from those "over thirty" to those "over ninety" also underscores the cyclical nature of generational conflicts and the changing perceptions of age-based authority.

John McCarthy is an influential figure in computer science, known for his pioneering work on artificial intelligence (AI) and programming languages like Lisp. He was a key player in the development of early AI theories and algorithms, contributing significantly to the field's foundational concepts. His insights extend beyond technology; he often commented on broader societal issues, as reflected in this quote about generational mistrust.