The attack and defense games.

The attack-and-defense game is a game in which an attacker (a group of attackers) has an incentive to revise the status quo and a defender (a group of defenders) wants to protect it. The asymmetry in objectives creates incompatible interests and results in a mixed-strategy Nash equilibrium. However, this equilibrium could be heavily impacted by behavioral considerations.

Predictable and predictive emotions: explaining cheap signals and trust re-extension.

Despite normative predictions from economics and biology, unrelated strangers will often develop the trust necessary to reap gains from one-shot economic exchange opportunities. This appears to be especially true when declared intentions and emotions can be cheaply communicated. Perhaps even more puzzling to economists and biologists is the observation that anonymous and unrelated individuals, known to have breached trust, often make effective use of cheap signals, such as promises and apologies, to encourage trust re-extension.

You can't put old wine in new bottles: the effect of newcomers on coordination in groups.

A common finding in social sciences is that member change hinders group functioning and performance. However, questions remain as to why member change negatively affects group performance and what are some ways to alleviate the negative effects of member change on performance? To answer these questions we conduct an experiment in which we investigate the effect of newcomers on a group's ability to coordinate efficiently. Participants play a coordination game in a four-person group for the first part of the experiment, and then two members of the group are replaced with new participants, and the newly formed group plays the game for the second part of the experiment.