  Members of social networks are given opportunities to bestow positive
recognition upon one another by means of constructs such as "likes" and
"retweets." Although recipients no doubt experience utility from these actions,
one might question why these constructs with no intrinsic value for the sender
are exchanged at all. Here we formulate a metric for the prestige of a member
of a social network based on his or her place within the network and the rate
at which "likes" are exchanged within his or her social circle. Simulation
reveals that the 1% most strategically-optimized networks exchange likes at an
average rate 23.5% higher than that of their random counterparts. This suggests
that purely strategic agents, even with no concern for altruism or the general
welfare, experience utility from giving social gratification. Further, we show
that prestige-maximization creates a selective pressure for structural features
associated with social networks including clustering and the small-world
property.
