|
Three Degrees of Influence is a theory in the realm of social networks, proposed by Nicholas A. Christakis and James H. Fowler in 2007. Christakis and Fowler found that social networks have great influence on individuals' behavior. But social influence does not end with the people to whom a person is directly tied. We influence our friends, who in their turn influence their friends, meaning that our actions can influence people we have never met. They posit that "everything we do or say tends to ripple through our network, having an impact on our friends (one degree), our friends’ friends (two degrees), and even our friends’ friends’ friends (three degrees). Our influence gradually dissipates and ceases to have a noticeable effect on people beyond the social frontier that lies at three degrees of separation". This argument is basically that peer effects need not stop at one degree, and that, if we can affect our friends, then we can (in many cases) affect our friends' friends, and so on. However, across a broad set of empirical settings, the effect seems to no longer be meaningful at a social horizon of three degrees. Christakis and Fowler examined phenomena from various domains, such as obesity, happiness, cooperation, and politics; investigations by other groups have explored many other phenomena in this way. ==Mechanism== The influence of actions ripples through networks three degrees (to and from your friends’ friends’ friends). Influence dissipates after three degrees for three reasons, Christakis and Fowler propose:〔(''Connected Preface+chapter1'' )〕 # Intrinsic decay - corruption of information (like the game telephone). # Network instability - social ties become unstable (or are not constant across time) at more than three degrees of separation. # Evolutionary purpose - we evolved in small groups where everyone was connected by three degrees or fewer (an idea receiving subsequent support 〔Morgan TJH et al, Experimental evidence for the co-evolution of hominin tool-making teaching and language. Nature Communications 2015; 6: 6029〕). 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Three degrees of influence」の詳細全文を読む スポンサード リンク
|