Research Images

Obesity in a Face-to-Face Network in 2000

1-3This graph shows the largest connected subcomponent involving 2,200 individuals in 2000 from the Framingham Heart Study Social Network. Each node represents one person. Nodes with blue borders are men and those with red borders are women. The size of each node is proportional to the person’s body-mass index. The interior color of the circles indicates the person’s obesity status: yellow denotes an obese person (body-mass index, ≥30) and green denotes a non-obese person. The colors of the ties between the nodes indicate the relationship between them: purple denotes a friendship or marital tie and orange denotes a familial tie (e.g., siblings). Clusters of obese and non-obese individuals are visible in the network, as confirmed by mathematical models discussed in the paper. These clusters are not only due to individuals of similar body size preferentially forming ties, but also due to influence, whereby one person’s body size affects that of another. For more details, see: N.A. Christakis and J.H. Fowler, “The Spread of Obesity in a Large Social Network Over 32 Years,” New England Journal of Medicine 2007; 35: 370-379. [download hi-res]

Obesity in a Facebook Network

2This graph shows a subcomponent drawn from a network of 1,700 undergraduate students whose social ties were ascertained using Facebook. Each node represents one person and ties between them indicate a close friendship. Square nodes are men and circular nodes are women. The interior color of the nodes indicates the person’s obesity status: red denotes an obese person, orange an overweight person, yellow an underweight person, and white a normal-sized person. Clusters of obese and non-obese individuals are visible in this online network. For more details about the dataset, see: K. Lewis, J. Kaufman, M. Gonzalez, A. Wimmer, and N.A. Christakis, “Tastes, Ties, and Time: A New (Cultural, Multiplex, and Longitudinal) Social Network Dataset Using Facebook.com,” Social Networks 2008; 30: 330-342. For more about obesity in the network, see Facebook, Obesity, and Your Friends’ Friends. [download hi-res]

Smoking in a Face-to-Face Network in 1971

3This graph shows a sample of 1,000 individuals selected from the largest connected subcomponent in 1971 from the Framingham Heart Study Social Network. Each node represents one person. Each circle (node) represents one person. Circles with red borders denote women, and circles with blue borders denote men. The interior color of the circles indicates the person’s cigarette consumption (yellow denotes ≥1 cigarette per day, and green denotes no cigarettes). The size of each circle is proportional to the number of cigarettes consumed. The colors of the ties between the circles indicate the relationship between them: orange denotes a friendship or a marital tie, and purple denotes a familial tie. For more details, see: N.A. Christakis and J.H. Fowler, “The Collective Dynamics of Smoking in a Large Social Network,” New England Journal of Medicine 2008; 358: 2249-2258. [download hi-res]

Smoking in a Face-to-Face Network in 2000

4This graph shows a sample of 1,000 individuals selected from the largest connected subcomponent in 2000 from the Framingham Heart Study Social Network. Each node represents one person. Each circle (node) represents one person. Circles with red borders denote women, and circles with blue borders denote men. The interior color of the circles indicates the person’s cigarette consumption (yellow denotes ≥1 cigarette per day, and green denotes no cigarettes). The size of each circle is proportional to the number of cigarettes consumed. The colors of the ties between the circles indicate the relationship between them: orange denotes a friendship or a marital tie, and purple denotes a familial tie. By 2000, smokers were more likely to appear at the periphery of their networks; in addition, smokers are usually in smaller subgroups than nonsmokers. For more details, see: N.A. Christakis and J.H. Fowler, “The Collective Dynamics of Smoking in a Large Social Network,” New England Journal of Medicine 2008; 358: 2249-2258. [download hi-res]

A Cluster of Smokers in a Face-to-Face Network in 2000

5This graph shows a close-up of a cluster of nodes from the Framingham Heart Study Social Network in the year 2000. Each circle (node) represents one person. Circles with red borders denote women, and circles with blue borders denote men. The interior color of the circles indicates the person’s cigarette consumption (yellow denotes ≥1 cigarette per day, and green denotes no cigarettes). The size of each circle is proportional to the number of cigarettes consumed. The colors of the ties between the circles indicate the relationship between them: orange denotes a friendship or a marital tie, and purple denotes a familial tie. Smokers are more likely to appear at the periphery of their networks. For more details, see: N.A. Christakis and J.H. Fowler, “The Collective Dynamics of Smoking in a Large Social Network,” New England Journal of Medicine 2008; 358: 2249-2258. [download hi-res]

 

6This graph shows another close-up of a cluster of nodes from the Framingham Heart Study Social Network in the year 2000. Each circle (node) represents one person. Circles with red borders denote women, and circles with blue borders denote men. The interior color of the circles indicates the person’s cigarette consumption (yellow denotes ≥1 cigarette per day, and green denotes no cigarettes). The size of each circle is proportional to the number of cigarettes consumed. The colors of the ties between the circles indicate the relationship between them: orange denotes a friendship or a marital tie, and purple denotes a familial tie. Smokers are more likely to appear at the periphery of their networks. For more details, see: N.A. Christakis and J.H. Fowler, “The Collective Dynamics of Smoking in a Large Social Network,” New England Journal of Medicine 2008; 358: 2249-2258. [download hi-res]

Happiness in a Face-to-Face Network in 1996

7This graph shows the largest connected subcomponent of friends, spouses, and siblings involving 1,181 individuals in 1996 from the Framingham Heart Study Social Network. Each node represents one person (circles are female, squares are male). Lines between nodes indicate relationship (black for siblings, red for friends and spouses). Node color denotes the happiness of the subject, with blue shades indicating the least happy and yellow shades indicating the happiest individuals (shades of green are intermediate). The graph suggests clustering in happiness and unhappiness within the network, and it suggests a relationship between being peripheral and being unhappy, both of which are confirmed by statistical models discussed in the paper. For more details, see: J.H. Fowler and N.A. Christakis, “Dynamic Spread of Happiness in a Large Social Network: Longitudinal Analysis Over 20 Years in the Framingham Heart Study,” British Medical Journal 2008; 337: a2338 (doi:10.1136/bmj.a2338). [download hi-res]

Happiness in a Face-to-Face Network in 2000

8This graph shows the largest connected subcomponent of friends, spouses, and siblings involving 1,020 individuals in 2000 from the Framingham Heart Study Social Network. Each node represents one person (circles are female, squares are male). Lines between nodes indicate relationship (black for siblings, red for friends and spouses). Node color denotes the happiness of the subject, with blue shades indicating the least happy and yellow shades indicating the happiest individuals (shades of green are intermediate). The graph suggests clustering in happiness and unhappiness within the network, and it suggests a relationship between being peripheral and being unhappy, both of which are confirmed by statistical models discussed in the paper. For more details, see: J.H. Fowler and N.A. Christakis, “Dynamic Spread of Happiness in a Large Social Network: Longitudinal Analysis Over 20 Years in the Framingham Heart Study,” British Medical Journal 2008; 337: a2338 (doi:10.1136/bmj.a2338). [download hi-res]

Loneliness in a Face-to-Face Network in 2000

9This graph shows the largest connected subcomponent of friends, spouses, and siblings involving 1,019 individuals in 2000 from the Framingham Heart Study Social Network. Each node represents one person, and its shape denotes gender (circles are female, squares are male). Lines between nodes indicate relationship (red for siblings, black for friends and spouses). Node color denotes the mean number of days the individual felt lonely in the past week, with yellow being 0–1 days, green being 2 days, and blue being 3 days or more. The graph suggests clustering in loneliness and a relationship between being peripheral and feeling lonely, both of which are confirmed by statistical models discussed in the paper. For more details, see: J.T. Cacioppo, J.H. Fowler, and N.A. Christakis, “Alone in the Crowd: The Structure and Spread of Loneliness in a Large Social Network,” Journal of Personality and Social Psychology 2009; 97: 977-991. [download hi-res]

Taste in Books in a Facebook Network

10This graph shows a subcomponent drawn from a network of 1,700 undergraduate students whose social ties were ascertained using Facebook. Each node represents one person and ties between them indicate a close friendship. The interior color of the nodes indicates the person’s taste in books. For more details about the dataset, see: K. Lewis, J. Kaufman, M. Gonzalez, A. Wimmer, and N.A. Christakis “Tastes, Ties, and Time: A New (Cultural, Multiplex, and Longitudinal) Social Network Dataset Using Facebook.com” Social Networks 2008; 30: 330-342. For more about the spread of tastes on Facebook, see ConnectedtheBook.com. [download hi-res]

Taste in Movies in a Facebook Network

11This graph shows a subcomponent drawn from a network of 1,700 undergraduate students whose social ties were ascertained using Facebook. Each node represents one person and ties between them indicate a close friendship. The interior color of the nodes indicates the person’s taste in movies. For more details about the dataset, see: K. Lewis, J. Kaufman, M. Gonzalez, A. Wimmer, and N.A. Christakis, “Tastes, Ties, and Time: A New (Cultural, Multiplex, and Longitudinal) Social Network Dataset Using Facebook.com,” Social Networks 2008; 30: 330-342. For more about the spread of tastes on Facebook, see ConnectedtheBook.com. [download hi-res]

Taste in Music in a Facebook Network

12This graph shows a subcomponent drawn from a network of 1,700 undergraduate students whose social ties were ascertained using Facebook. Each node represents one person and ties between them indicate a close friendship. The interior color of the nodes indicates the person’s taste in music. For more details about the dataset, see: K. Lewis, J. Kaufman, M. Gonzalez, A. Wimmer, and N.A. Christakis, “Tastes, Ties, and Time: A New (Cultural, Multiplex, and Longitudinal) Social Network Dataset Using Facebook.com,” Social Networks 2008; 30: 330-342. For more about the spread of tastes on Facebook, see ConnectedtheBook.com. [download hi-res]

Smiling in a Facebook Network

13This graph shows a subcomponent drawn from a network of 1,700 undergraduate students whose social ties were ascertained using Facebook. Each node represents one person and ties between them indicate a close friendship. Node color denotes the happiness of the subject, with blue shades indicating the least happy and yellow shades indicating the happiest people (shades of green are intermediate). The graph suggests clustering in happiness and unhappiness within this online network, and it suggests a relationship between being peripheral and being unhappy. For more details, see: N.A. Christakis and J.H. Fowler, “Social Network Visualizations in Epidemiology,” Norwegian Journal of Epidemiology 2009; 19: 5-16. [download hi-res]

Drinking in a Face-to-Face Network in 2000

14 (low)A sample of the largest component of friends, spouses, and siblings at examination 7 (centered on the year 2000); 1073 individuals are shown. Each node represents 1 person. The graph suggests clustering in abstention and heavy alcohol consumption behavior, both of which are confirmed by statistical models. For more details, see: N.A. Christakis and J.H. Fowler, “The Spread of Alcohol Consumption Behavior in a Large Social Network,” Annals of Internal Medicine 2010; 152: 426-433. [download]