This document analyzes Twitter conversation networks among members of Congress. It finds that Republicans, Senators, and males are more likely to mention members of the opposing party or chamber in their tweets. Senators and males are also more likely to mention members of the opposing party. The networks indicate low cohesion among members and that a small subset of members are explicitly engaged by others, reflecting that Twitter is used more for selective outreach than broadcasting to all members. Overall, the networks on Twitter do not show more polarization than political blogs and represent new media being used for existing behaviors rather than entirely novel political interactions.

1. COMMUNITY STRUCTURE IN
CONGRESSIONAL
CONVERSATION NETWORKS
Or, the paper formerly known as
Relationships Among Twitter Conversation
Networks, Language Use, and Congressional
Voting
Libby Hemphill, Jahna Otterbacher, and
Matthew Shapiro

2. What do we expect to see?
• Interaction with constituents 5,8,10
• Polarization, divided communities 1,3,4,8
• More activity among Republicans 9
• More activity among Senators 9
• Similar presentations among men and women 7

3. Legend for graphs
Edge Properties
Color Gray = same party
Yellow = different parties
Node Properties
Color Red = Republican
Blue = Democrat
Yellow = Independent
Shape Solid square = House
Solid circle = Senate
Size In degree
Opacity Out degree

4. April 12, 2012 Shapiro, Hemphill, and Otterbacher
Congress mentioning each other:
Excluding self-loops

5. April 12, 2012 Shapiro, Hemphill, and Otterbacher
Congress mentioning each other:
including self-loops

6. April 12, 2012 Shapiro, Hemphill, and Otterbacher
House only

7. April 12, 2012 Shapiro, Hemphill, and Otterbacher
Senate only

8. Predicting Connections
(1) (2) (3) (4)
crossparty crosschamber crossparty crosschamber
Republican -0.308*** 0.107** -0.325*** 0.0908**
(-12.86) (3.27) (-13.15) (2.71)
Senate 0.172*** 2.715*** 0.180*** 2.724***
(5.46) (74.83) (5.69) (74.48)
Male 0.0925** 0.0944*
(2.79) (2.12)
_cons -0.230*** -1.943*** -0.299*** -2.014***
(-12.21) (-71.46) (-9.62) (-46.26)
N = 29,597
t statistics in parentheses
* p < 0.05, ** p < 0.01, *** p < 0.001

9. Results
• Low density indicates low cohesion 6
• Republicans, Senators, and males more likely to
mention across chambers
• Senators and men more likely to mention across
party lines
• Conservatives mention each other more 1
• Explicitly engage small subset of those under
surveillance 2

10. Takeaways
• New medium, not new behavior 11
• Congress less polarized than political blogosphere 1
• Echo chamber more than broadcast medium

11. Contact us
• Libby Hemphill (libby.hemphill@iit.edu)
• Jahna Otterbacher (jotterba@iit.edu)
• Matt Shapiro (mshapir2@iit.edu)
• Illinois Institute of Technology
• info@casmlab.org
• http://www.casmlab.org/projects/publicofficials/

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