Reduced aggression toward territorial neighbors, termed the dear-enemy effect, is thought to arise because territorial animals benefit by avoiding contests with neighbors with whom they have already established relationships. The dearenemy effect has been described in many taxa, but few studies have considered whether or not neighbors relationships are affected by changes in the social environm...

We present a novel problem of searching for ‘familiar strangers’ in a social network. Familiar strangers are individuals who are not directly connected but exhibit some similarity. The power-law nature of social networks determines that majority of individuals are directly connected with a small number of fellow individuals, and similar individuals can be largely unknown to each other. Moreover...

Given the reliance on self-report in studies of adults with intellectual disabilities, this study examined individual vs. parental reports concerning the social approach behaviors of adults with Williams syndrome (WS) across a hypothetical and a live behavioral setting. Individuals with WS (N = 30) were asked whether they would approach strangers in two hypothetical, laboratory tasks (yes/no qu...

Many economic decisions are susceptible to either free-riding, or excessive rivalry or overextraction. Equally sharing output in partnerships introduces a free-riding incentive which may offset the latter. We conduct a laboratory experiment to assess the performance of output sharing in partnerships by introducing equal-sharing subgroups of size one, four and six into a twelve-person common poo...

We conduct online field experiments in large real-world social networks in order to decompose prosocial giving into three components: (1) baseline altruism toward randomly selected strangers, (2) directed altruism that favors friends over random strangers, and (3) giving motivated by the prospect of future interaction. Directed altruism increases giving to friends by 52 percent relative to rand...

Neighboring territorial animals are viewed primarily as intense rivals, but there are also opportunities for cooperation among competitors. Many animals respond less aggressively toward neighbors than to strangers. This phenomenon, termed the ‘‘dear enemy’’ effect, should be stable only when the reduced aggression is reciprocal. Territory owners should use conditional strategies in territorial ...

Research in animals and humans suggests a role of oxytocin in social approach to strangers. We tested this by introducing undergraduate students to opposite-gendered strangers, with each member of the pair having taken either oxytocin or placebo. One hundred and four undergraduate students were paired up and engaged in a face-to-face conversation structured with a series of intimate topics for ...

Many interactions in modern human societies are among strangers. Explaining cooperation in such interactions is challenging. The two most prominent explanations critically depend on individuals' willingness to punish defectors: In models of direct punishment, individuals punish antisocial behavior at a personal cost, whereas in models of indirect reciprocity, they punish indirectly by withholdi...

Friendship plays a critical role in social commerce in contemporary societies. This study aims to theorize and examine how friendship quality impacts purchase intention. Product-related risk is introduced to gain insight into its moderating effects on intention to purchase from three different seller groups. Through empirical evidence, we confirm that friendship quality has positively effect on...