To show that indirect reciprocity can stabilize collective action without the second-order free rider problem, we consider a large population subdivided into randomly formed social groups of size n.

Human societies are organized around cooperative interactions. But why would natural selection equip selfish individuals with altruistic tendencies? This question has fascinated evolutionary ...

Currently, global health is failing in equity, reciprocity, and genuine bi-directional partnerships. Global health is dominated by individuals and institutions in high-income countries (HICs) who ...

When you share your lunch with someone less fortunate or give your friend half of your dessert, does that act of generosity flow from the milk of human kindness, or is it a subconscious strategy to ...

When you hear the word “give” at work, people instinctively reach for their wallets or purses, either to open or hide them. Giving is something inherent in the human psyche. It may be that within each ...

Learn about the Constitutional Concealed Carry Reciprocity Act. It would allow licensed permit holders to carry handguns ...

Shaneen Allen, a Philadelphia mother of two, was arrested during a traffic stop three years ago after she crossed from Pennsylvania into New Jersey with a loaded .380-caliber Bersa Thunder handgun -- ...

Tariffs are back in the headlines, and the noise is loud. The question I keep hearing is simple: will they help or hurt? My view is clear. Tariffs only work when policy is steady, signals are clear, ...

The Trace reports on concealed carry reciprocity, and what it means if Congress passes a bill effectively allowing the residents of 29 permitless carry states to carry guns nationwide without a ...

Finally, after many long years, law and order is returning to our nation’s capital. In March, President Trump signed an executive order to “Make the District of Columbia Safe and Beautiful,” and part ...