A tension exists between adults’ natural desire to keep children safe and the apparently natural need for children to develop their risk-taking abilities by engaging in adventurous play. The first step towards determining what is the appropriate level of risk for children is to categorize the various types play in which they engage.

During the 1960s and 1970s, protest was central to American political discourse — against the Vietnam War, for the environment and women’s rights, against the abuse of political power. The Reagan years added social issues to the range of contentious subjects, but large-scale protest fell out of favor in the 1990s.

The rise in global competition between nations has highlighted the importance of research and development spending for fostering economic growth and development.

Social media have transformed corporate communication practices: Tools such as Twitter and Facebook allow organizations to speak directly to and solicit responses from the public quickly and affordably. But the original intention of these media were to connect friends, not customers or employees; for businesses, accustomed to managing all aspects of communications (and muting dissent), social media can be an awkward fit.

As the Internet plays a larger role in governance, campaigns and activism, the debate continues about how social and digital media are changing politics. Ongoing research is addressing topics such as whether or not the Internet is leading to increased political polarization — the tendency of like-minded individuals to cluster even closer together in their habits and viewpoints.