TV programs that denounce unfair advantage impact women's sensitivity to defection in the public goods game.

We explore the neural underpinnings of gender differences in cooperation and their modulation by intensive media watching. We compared cooperative decisions and electroencephalograph data between genders from who participated in repeated rounds of the public goods game (PGG) and investigated within groups changes that occurred after watching a TV program known as "investigative reporting" that denounces unfair advantages taken by free-riders against the public. Women tended to be more cooperative than men during early rounds of PGG, mostly because they react differently to the defection of others; women also had greater β and γ band activity in regions estimated to be associated with social cognition. These gender differences disappeared after participants watched the TV programs: women were more likely to choose free-riding in response to the defection of others that elicits significant increases in γ band activities that were estimated to be right insula. Greater activity in social cognition leads women to make decisions considering the motives of others, while men tend to make a decision by complying with the social norm. Watching the investigative TV reports produced a greater negative emotion to the defection and led women, in a similar manner as men, to opt for a "tit-for-tat" strategy.