ɫɫÀ²

News

Nicholas Christakis: Friends are like us

As friends, people choose other people who remind them of themselves.

We also create communities that reinforce our tendency to choose friends who are similar to ourselves.

For example, if our friends are overweight, we have a 45% likelihood of being overweight. If the friends of our friends are overweight, our probability of being overweight increases by 20%.

Researchers have also proven that happy people are often surrounded by a lot of happy people and unhappy people are surrounded by unhappy people. This can be a sign of friend selection and also of how emotions spread in networks.

The power of networks is also visible in an experiment performed by researchers that measured the spreading of friendly acts in a network. When people were treated positively, they were friendly to others as well. A chain reaction can mean that treatment of a person may depend on how two people that are complete strangers to him/her have treated each other.

Watch Christaki's talk .

  • Updated:
  • Published:
Share
URL copied!

Read more news

Close-up of a complex gold-coloured machine with various wires and connectors.
Research & Art Published:

What does ‘quantum’ mean?

Two quantum researchers at Aalto University explain how the seemingly impossible becomes a part of everyday reality.
Samu Taulu
Appointments, Research & Art Published:

Samu Taulu develops next-generation brain imaging methods

Associate Professor of neurostimulation and neuroimaging Samu Taulu develops more precise methods for understanding the brain
Four students sitting on outdoor steps, talking and laughing with books and a tablet by modern buildings
Studies Published:

Aalto University and Bocconi University to launch a double degree programme in strategic and creative marketing

The first cohort, 10 students admitted through Aalto and 10 through Bocconi, will start their studies in autumn 2027
Annika Blomqvist
Awards and Recognition Published:

The Business Leader of the Year 2026 is Annikka Hurme, CEO of Valio

In addition, Annika Blomqvist was awarded for promoting entrepreneurship and Sanni Mustonen for her excellent master’s thesis.