Information Cascades in Animal Populations
Individual humans have their own thoughts, ideas, and opinions, yet being grouped or connected with others, in others words being part of a network, can have an affect on these individuals’ decision making processes. Being in a network introduces a new opportunity to imitate or copy the decisions of others. Individuals can either follow their own original private information and ideas, or they can follow the crowd, yet there is no right or wrong answer. Individuals deciding to follow the crowd, and simultaneously deciding not to listen to their own informational signs, ideas, or initial thoughts that may not align with the flow of the crowd, is the main idea of an information cascade.
Rational reasons humans may tend to follow the crowd rather than their own information are usually either direct benefits, when being part of a crowd has benefits in itself, or information-based, reasoning about what people in the crowd know. When humans follow a crowd with the goal of simply being in the crowd, for instance to meet other people or to feel like there is safety in numbers, this is a direct benefit. This same concept of information cascades and following a crowd for direct benefits can actually be applied to animal populations as well. Although not researched as thoroughly or explained in as much detail as in humans, in their paper “A Theory of Fads, Fashion, Custom, and Cultural Change as Informational Cascades”, Sushil Bikhchandani, David Hirshleifer, and Ivo Welch, describe how some animals tend to live in “clusters” rather than in separated territories. The reasoning behind this “clustering” is that animals simply like to live where other animals have previously settled and still currently live. This idea is very similar to humans following a crowd simply to be with others, a direct benefit.
Furthermore, when humans follow a crowd with the goal of optimizing their information because they want to know what other people know or the reasons behind others’ decisions, this is an information-based imitation. Just like humans, Bikhchandani, Hirshleifer, and Welch describe how some other animals can also decide to live in “clusters” due to information-based imitation. As referenced in the paper, male animals specifically may choose to live in an area where many other animals have also already inhabited based on the idea that the animals living in that area may have some information as to why this area is a good place to live. Highly “clustered” areas, where many males already live, indicate to other incoming males that there are most likely plentiful resources in this area and closely surrounding areas.
Sources and Links:
Easley, David, and Jon Kleinberg. Networks, Crowds, and Markets Reasoning about a Highly Connected World. Cambridge University Press, 2016.
Bikhchandani, Sushil, et al. “A Theory of Fads, Fashion, Custom, and Cultural Change as Informational Cascades.” The Journal of Political Economy, vol. 100, Oct. 1992.
https://www.unc.edu/~fbaum/teaching/articles/Bikhchandani_etal_1992_JPE.pdf