Information cascades and Overheard at Cornell
Overheard groups are Facebook groups for colleges where people post things hilarious, stupid or sexual on campus. Various colleges have this groups but it originally originated from University of Western Ontario, Canada. A particular group I’m referencing in this post is the Overheard at Cornell group. https://www.facebook.com/groups/overheardatcornell/ (Need a Cornell NetID to log on).
There is a peculiar thing about likes in this group and in Facebook in general, but I’m limiting my argument to this group. The more likes you have initially, the greater likes you have later. This leads to a huge disparity in the number of likes for various posts on a simple thread. In general, the witty posts usually have the most likes, and other ones well… not too many.
This usually starts with a few people liking the posts. The first person is indifferent and likes the post of his own volition. The second person won’t really base his decision on just one like and would in turn like the post if he finds it witty. The third person on the other hand already sees two likes and he might initially not have thought the post was witty or funny but when he sees two people liking the post, he feels they have information he doesn’t, he thinks about the post for a few seconds and then he likes it. The fourth person and beyond usually do the same and in the end you have a really witty post having a huge number of likes and the others not.
For example, a person posted this picture.
I didn’t get it at all but I saw it had considerable likes, so there had to be a reason it popular. The glass thingy is a tower and the chalk drawing is …, well I thought about it for a few seconds and I got it, so I immediately liked it. A day after, it seemed everyone did the same as I did because:
However, for a fairly unpopular post that didn’t have considerable likes:
I didn’t like it and a week after, turns out every one did as I did because:
This phenomenon demonstrates the power of information cascade.