Lynch first developed the themes of
Thought Contagion in his 1979 undergraduate senior thesis entitled "Abstract
Evolution." The thesis explored the notion that an idea which can influence
human behavior may blindly evolve the capacity to influence its own prevalence in the human population by motivating its human hosts to engage in behavior that spreads the idea. Just as a
virus which elicits sneezes from its human host is more likely to survive by passing from host to host than a similar but non-sneeze-provoking virus, Lynch hypothesized that an
idea which stimulated its host to
proselytize, e.g., "Go and make disciples of all nations" (
Gospel of Matthew 28:19), would be more likely to survive and become popular than an idea which did not elicit such activity. He identified other mechanisms which might also increase an idea's
market share and longevity, such as influencing the human host to produce more children than it otherwise would, to instruct one's children in the belief earlier and more rigorously than one otherwise might, to isolate or effectively immunize oneself or one's children from exposure to competing ideas, to actively impede the communications of nonbelievers, or to utilize mass communications
media to spread the idea to people that the host would never personally meet.
Cultural anthropology had long held that cultural beliefs and information—i.e., socially propagated ideas—survive and propagate because of the survival value they provide to the human groups that adopt them. Lynch embraced this notion of host-benefiting idea propagation, but his analysis added to this the notion that ideas could also propagate at the expense of their human hosts. He noted, for example, that beliefs which induced their hosts into
self-sacrifice before sufficiently large audiences (e.g. earlier
Christians refusing to worship the Emperor and
dying serenely in Roman arenas or
Islamist suicide bombers taping farewell videos for posthumous broadcast to worldwide audiences) could survive or even multiply just by capturing one or more hosts to replace the one it sacrificed. Lynch questions whether ideas might be "shopping" for humans as well as vice versa, and asked whether humans own their most cherished beliefs or the beliefs own them. However, Lynch stopped short of suggesting that ideas have consciousness, will or planning abilities. To Lynch, ideas were information encoded in human
neurons or other media. Like
computer viruses, they are the products of human thinking and are in no way aware of or deliberating controlling their self-replicating abilities. However, unlike computer viruses, ideas often evolve new or improved contagious properties without intentional
human design, through copying infidelity mutations or recombination into powerful new belief sets. According to Lynch,
Natural selection determines which ideas survive and propagate successfully through human populations and which lose market share to the point of extinction. Lynch's thesis offered an explanation for how not only
true and useful ideas, but also unprovable or even
false notions with sufficiently "contagious" properties could, over generations, become the predominant beliefs of whole societies. While he insisted that the contagiousness of ideas was largely independent of their
truth value, as he immersed himself in this analysis, his frequently uttered motto became, "People don't learn from each other's mistakes. They learn each other's mistakes." ==Reception and criticism==