Excellent examples of the information cascade phenomenon seem to be popping up frequently in recent blog posts. The more one learns about this powerful concept, the more one begins to see its effect on a diversity of societal trends. As we’ll see, the results of these effects are not always positive.

Blogger timewalker points out an article from the New York Times about the upcoming presidential primaries. Historically, states with earlier elections have a stronger effect on the overall outcome of the race. The results of these initial elections affect the likelihood that a given candidate will win, beginning a cascade in which voters jump on the bandwagon to support the stronger nominee. Several states have begun vying to be the earliest start voting.

An article from the Harvard News Office posted by nps26 discusses the results of a study on obesity in social networks. In particular, the authors suggest that having overweight friends and family members increases the chances of being overweight yourself. Acquaintances who “mutually describe each other as friends” had the highest probability of weight gain, prompting the conclusion that “the acceptability of gaining weight” was a “changing norm” which cascades through social bonds.

A particularly negative effect of information flow, the tendency for suicides to be “contagious,” was brought up by nondeplume9. A paper published in 2002 points out the spike in the suicide rate among Micronesian children between 1960 and 1989. The author claims that a couple of high profile cases triggered an epidemic of suicides, some for seemingly trivial reasons. One explanation presented by the paper for these trends is that simply having the idea of suicide disseminated in public makes it somehow more palatable to depressed and impressionable youths.

Humans are not the only species capable of information cascades, as demonstrated in a post by mrjeets regarding the fate of army ants separated from the group. The linked article discusses how confused workers rely on their deeply ingrained tendency to follow the ant in front of them. When a group becomes isolated, they “run in a densely packed circle,” with the lead ant begins to follow the trailing ant, indefinitely, “until they all die from exhaustion.”