The concept of “six degrees of separation” suggests that any two people on Earth are, on average, connected through a chain of no more than six acquaintances. This idea highlights the interconnectedness of human relationships and the small world phenomenon. Here’s a deeper look at the concept:

Origin and Development

  1. Original Concept:
    • The theory was first proposed by Hungarian writer Frigyes Karinthy in his 1929 short story “Chains.” He suggested that the modern world was ‘shrinking’ due to increasing connectedness among people.
  2. Mathematical Formulation:
    • The concept was formalized mathematically in the 1960s, largely influenced by the work of mathematicians and sociologists who studied network theory and graph theory.

Key Experiments and Studies

  1. Milgram’s Experiment:
    • In the 1960s, psychologist Stanley Milgram conducted an experiment where he asked people to send a letter through their acquaintances to a stranger in a different city. On average, the letters reached the target person through six intermediaries, popularizing the “six degrees” notion.
  2. Watts and Strogatz:
    • In the late 1990s, Duncan Watts and Steven Strogatz further explored small-world networks and published their findings, showing how networks can be highly clustered yet have short path lengths between nodes, corroborating the six degrees concept.

Modern Applications and Digital Age

  1. Social Networks:
    • The rise of social media platforms like Facebook and LinkedIn has provided extensive data to study the six degrees theory. Studies on these platforms often find that the degrees of separation are even fewer, typically around 3 to 4.
  2. Impact on Technology:
    • The six degrees concept influences algorithms in social networking services, search engines, and recommendation systems by leveraging the interconnectedness of users to improve connections and suggestions.

Cultural Impact

  1. Popular Culture:
    • The idea has permeated popular culture, with references in films, books, and games. For example, the game “Six Degrees of Kevin Bacon” challenges players to connect any actor to Kevin Bacon through their film roles within six steps.
  2. Global Perspective:
    • The concept encourages a global perspective, emphasizing how close we are to anyone in the world, fostering a sense of global community and shared humanity.

Criticisms and Limitations

  1. Oversimplification:
    • Critics argue that the six degrees concept oversimplifies the complexity of human relationships and social networks. Factors like geography, social status, and cultural barriers can significantly influence the degrees of separation.
  2. Data Bias:
    • Studies often rely on data from social networks, which may not represent the entire population accurately. These networks are also influenced by self-selection bias and the nature of online versus offline relationships.

In summary, the six degrees of separation concept illustrates the surprising closeness of human connections and has profound implications for understanding social networks and fostering a sense of global interconnectedness. Despite criticisms, it remains a powerful metaphor for the potential reach of our social connections.


The concept of “six degrees of separation” refers to the idea that all people are six or fewer social connections away from each other.

The theory was first proposed in 1929 by the Hungarian writer Frigyes Karinthy, although the phrase “six degrees of separation” wasn’t coined until the 1990s. It’s based on the notion that the world is highly interconnected – you know some people, who know other people, who know yet other people, and so on. Through a few links in this chain, everyone is connected to anyone else in just a small number of steps.

Some key points about six degrees of separation:

The idea highlights our collective interconnectedness as a global society, while also reminding us how easy it can be to make connections and associations between disparate groups or individuals.