Despite the omnipresence of inter-group conflict, little is known about the underlying heterogeneity of individuals' group-dependent social preferences and their dynamics over time. Building on research in economics, psychology, and especially the interdisciplinary parochial altruism literature, we derive a typology of group-(in)dependent social preferences from the Social Value Orientation (SVO) model.

We propose six profiles of social preferences in relation to in-group members and out-group members. Three types do not differentiate between in-group and out-group members in their preferences: Universal Altruists, Universal Egoists, and Universal Competitors, who are altruistic, egoistic, or spiteful, respectively, irrespective of others' group membership. In contrast, three other types have group-dependent preferences. These types show a greater concern for in-group members compared to out-group members. Weakly Parochial Altruists are prosocial toward in-group members and less so toward out-group members, but they do not have negative social preferences (i.e., competitiveness, aggression) toward the latter. Strongly Parochial Altruists are prosocial toward in-group members coupled with negative social preferences toward out-group members. Parochial Egoists are egoistic toward in-group members but are willing to forego some of their own gain to reduce the payoff of out-group members.

To identify the empirical prevalence of those types and the dynamics of group-dependent social preferences around and even years after a (political) conflict, we gather quota-representative, incentivized panel data from a field experiment during and after the heated 2016 Austrian presidential election. Concretely, we used the SVO Slider measure and matched subjects with both in- and out-group interaction partners (a voter of their own and the competing candidate, respectively) multiple times over the course of the conflict: in the week before the election, in the week after the election, three months after the election, and two years after the election.

We find a strong effect of the interaction partner’s group membership. In the week before the election, the average SVO angle is 24.9 degrees when matched with an in-group member and 8.8 degrees when matched with an out-group member (Cohen’s d = .8). Despite this strong effect of group membership, average in- and out-group SVO angles are remarkable stable over time, even for voters of the winning and the losing candidate separately.

At the individual level, we find considerable heterogeneity in our derived types: One week before the election, around 50% of our subjects have group-dependent social preferences. 13% of the subjects also care positively about the payoff of fellow in-group members, but are not willing to give up payoff for the benefit of out-group members (Weakly Parochial Altruists); 20% are Strongly Parochial Altruists, willing to reduce their own payoff for both the benefit of in-group members and the detriment of out-group members. 17% are Parochial Egoists, not willing to costly help in-group members but to costly hurt out-group members. 30% show a positive concern for the payoff of others, irrespective of group membership (Universal Altruists). Over time, only the share of Universal Egoists changes significantly (from 10% to 17%).