The article is from 2014 and it is about a paper studying "social effects in consumption" in a controlled situation (i.e. while you are stuck in an airplane), and another paper about social influences of high schoolers signing up for an SAT prep class.

While the studies are interesting, it is hardly worthy of the click-bait title.

TL;DR if you sit next to someone on an airplane who buys a drink you are 30% more likely to buy a drink yourself (and presumably the study successfully controlled for people traveling together).

Edit: The post title was just changed from what I clicked on "People around you control your mind: The latest evidence" which was so much more entertaining!