AreYouYourFriend’sFriend?
PoorPercep)onofFriendshipTiesLimitsTheAbilitytoPersuadeOthers
Abdullah Almaatouq, Laura Radaelli, Alex ‘Sandy’ Pentland & Erez Shmueli
Introduc)on
In this work, we show that the
direc0onalityandtopologyoffriendship
0es affect how effec0vely individuals
can influence the behavior of each
other. Moreover, we find that people
are typically poor at perceiving the
character of their friendship 0es and
that this can significantly limit their
ability to shape the behavior of others
and thus lead to failures in establishing
compa0ble norms, ac0ng together, or
finding compromise solu0ons and in
persuading others to act. We then
suggest strategies to overcome this
l i m i t a 0 o n b y u s i n g t o p o l o g i c a l
characteris0cs of the perceived
friendshipnetwork.
AnalysisMethodology
Friendshipnetwork
In0macyof0es
Results
Peer-pressure
C
Alter
perceived
friend
R-squared = 0.47
Gender
Tie
strength
Reciprocal
friend
Ego
perceived
friend
Age
Initial
activitiy
levels
Same-gender
friendship
Sameethnicity
friendship
Female = 0
Male = 1
Figure 1: (A) The undirected friendship nomina0on graph in the Friends and Family study, where nodes
representpar0cipantsandedgesrepresentfriendship.(B).CDFandKDEofclosenessscoresarecomputed
separatelyforunilateral0es(dashedorange)andreciprocal0es(solidblue). (C)Changeinphysicalac0vity
under experiment condi0ons shows that the type of friend- ship is relevant to the effec0veness of the
induced peer-pressure. The plot shows the mean effect size of the covariates (solid circles) and the 95%
confidenceintervals(bars).
E
Datasets
FriendsandFamily
•  15months,140par0cipants
F
•  Self-reported friendships, income
statusanddemographics.
•  Social incen0ves for promo0ng
physicalac0vi0es
Figure 2: In (A) and (B), we observe that Social Embeddedness (SE) and Social Centrality (SC) are good
discriminatorsbetweenreciprocalandunilateral0es,aswellasbetweenthetwodirec0onsofunilateral0es.
(C)and(D)showtheeffectofSEandSContheProbabilityofanegotoformareciprocal0eorbeperceivedas
afriend,respec0vely.MeanROCcurvesdemonstra0ngthemodelperformanceinpredic0ng0estype;(E)
showsthepredic0onforreciprocal0esand(F)showsthemodelperformanceinpredic0onincoming0es
Not All Friendships Are
Reciprocal
•  45%arereciprocal
•  Consistentacrossdatasets
ReciprocityandInducedPeerPressure
•  The strongest effect found
forthereciprocalfactor.
•  Egoperceivedasafriendby
the alters (i.e., incoming
edges to the subject), was
foundtobesignificant.
Predic)ngReciprocity
Socialfactorsthatcanbeused
to predict the type and
direc0onalityare:
•  Social Embeddedness: the
extent to which individuals
have an overlap of their
friendshipcircles;
•  S o c i a l C e n t r a l i t y : t h e
difference in the social
hierarchicalorganiza0on.