Social Influence on Decision Making

This is a summary of a lecture by Alex Paul Pentland at the 2011 "Innovations in Management" workshop at MIT Sloan School of Management. Alex Pentland is the Professor of Media Arts and Sciences and MIT’s head of the Human Dynamics Group. 

Prof. Pentland started off his lecture by talking about how humans make decisions: While we like to think of ourselves as logical and rational, research done by Prof. Pentland’s group found that we don’t make our decisions through sheer reason or intelligence at all; instead, we go around foraging for ideas, collecting and gathering them like squirrels. Then we vet those ideas, discuss them with the people we hang out with, and eventually use the ideas that look most attractive to us.


Yes, it’s true: we don’t decide through careful deduction or rationalization. And it’s not just people who we consider as our close friends who influence our decision, but more so, people we interact with on a daily basis. 

• People do what they see. We learn by mimicking – the old saying “monkey see, monkey do” applies to all of us. Prof. Pentland notes that in their studies, they found that people we do not even know can still be top influencers in our lives if they just happen to be working in the same office building as we do, or ride the same bus, or eat at the same restaurants.

  And definitely, these could be people we have never even spoken with. Picking ideas, habits any traits from each other is primarily not a verbal exercise. If you see somebody wearing a certain type of boot, then even if you hate her guts, it’s still entirely possible for you to like her boots and buy the same ones the next day without ever talking to her or consciously thinking about it. Similarly, if you see people at the lobby carrying cups of designer coffee with a certain brand, you’ve just caught an idea whether you are aware of it or not.

  It’s how we decide everything, from where to go for lunch, to what phone to buy, even whom to marry.