Every day, individuals around the world retrieve, share, and exchange information on the Internet. We interact online to share personal information, find answers to questions, make financial transactions, play social games, and maintain professional and personal relationships. Sometimes our online interactions take place between two or more humans. In other cases, we rely on computers to manage information on our behalf. In each scenario, risk and uncertainty are essential for determining possible actions and outcomes. This essay highlights common deficiencies in our understanding of key concepts such as trust, trustworthiness, cooperation, and assurance in online environments. Empirical evidence from experimental work in computer-mediated environments underscores the promises and perils of overreliance on security and assurance structures as replacements for interpersonal trust. These conceptual distinctions are critical because the future shape of the Internet will depend on whether we build assurance structures to limit and control ambiguity or allow trust to emerge in the presence of risk and uncertainty.

Privation and disease have mainly killed soldiers until very recently. Now that enemy action predominates, faster and better control of bleeding and infection before and during evacuation spares ever more lives today. This essay focuses on psychological war wounds, placing them in the context of military casualties. The surgeon's concepts of 'primary' wounds in war, and of would 'complications' and 'contamination', serve as models for psychological and moral injury in war. 'Psychological injury' is explained and preferred to 'Post-Traumatic Stress Disorder', being less stigmatizing and more faithful to the phenomenon. Primary psychological injury equates to the direct damage done by a bullet; the complications - for example, alcohol abuse - equate to hemorrhage and infection. Two current senses of 'moral injury' equate to wound contamination. As with physical wounds, it is the complications and contamination of mental wounds that most often kill service members or veterans, or blight their lives.

In contemporary America, racial gaps in achievement are primarily due to gaps in skills. Skill gaps emerge early before children enter school. Families are major producers of those skills. Inequality in performance in school is strongly linked to inequality in family environments. Schools do little to reduce or enlarge the gaps in skills that are present when children enter school. Parenting matters, and the true measure of child advantage and disadvantage is the quality of parenting received. A growing fraction of American children across all race and ethnic groups is being raised in dysfunctional families. Investment in the early lives of children in disadvantaged families will help close achievement gaps. America currently relies too much on schools and adolescent remediation strategies to solve problems that start in the preschool years. Policy should prevent rather than remediate. Voluntary, culturally sensitive support for parenting is a politically and economically palatable strategy that addresses problems common to all racial and ethnic groups.

Volunteers and charitable organizations contribute significantly to community welfare through their prosocial behavior: that is, discretionary behavior such as assisting, comforting, sharing, and cooperating intended to help worthy beneficiaries. This essay focuses on prosocial behavior on the Internet. It describes how offline charitable organizations are using the Net to become more efficient and effective. It also considers entirely new models of Net-based volunteer behavior directed at creating socially beneficial information goods and services. After exploring the scope and diversity of online prosocial behavior, the essay focuses on ways to encourage this kind of behavior through appropriate task and social structures, motivational signals, and trust indicators. It concludes by asking how local offline communities ultimately could be diminished or strengthened as prosocial behavior increases online.

In 1965, Daniel Patrick Moynihan, then an official in the Johnson administration, published "The Negro Family: The Case for National Action," better known as the Moynihan Report. He was influenced by his participation in two conferences organized by the American Academy of Arts and Sciences in the mid-1960s, as well as two issues of its journal Daedalus, on the topic of "The Negro American." Arguing that the "damaged" family structure of African Americans would impede efforts to achieve full racial equality in the United States, the Moynihan Report launched an explosive debate that helped fracture a fragile liberal consensus on civil rights. Geary examines the report alongside the Daedalus project, establishing its roots in the racial liberalism of the mid-1960s and connecting it to efforts by liberals to address the socioeconomic dimensions of racial inequality. He considers the close relationship between scholarship and public policy that existed at the time and reflects on the ways liberal ideas about race have changed in the decades since.

No one did more to draw neuroscientists' attention to the problem of consciousness in the twentieth century than Francis Crick, who may be better known as the co-discoverer (with James Watson) of the structure of DNA. Crick focused his research on visual awareness and based his analysis on the progress made over the last fifty years in uncovering the neural mechanisms underlying visual perception. Because much of what happens in our brains occurs below the level of consciousness and many of our intuitions about unconscious processing are misleading, consciousness remains an elusive problem. In the end, when all of the brain mechanisms that underlie consciousness have been identified, will we still be asking: "What is consciousness?" Or will the question shift, just as the question "What is life?" is no longer the same as it was before Francis Crick?

The standard account of American immigration focuses on the acculturation and assimilation of immigrants and their children to American society. This analysis typically ignores the significant contributions of immigrants to the creation of American culture through the performing arts, sciences, and other cultural pursuits. Immigrants and their children are not born with more creative talents than native-born citizens, but their selectivity and marginality may have pushed and pulled those with ability into high-risk career paths that reward creative work. The presence of large numbers of talented immigrants in Hollywood, academia, and the high-tech industries has pushed American institutions to be more meritocratic and open to innovation than they would be otherwise.

In this essay, Griffin brings to the fore two extraordinary black women of our age: First Lady Michelle Obama and entertainment mogul Beyoncé Knowles. Both women signify change in race relations in America, yet both reveal that the history of racial inequality in this country is far from over. As an Ivy League-educated descendent of slaves, Michelle Obama is not just unfamiliar to the mainstream media and the Washington political scene; during the 2008 presidential campaign, she was vilified as angry and unpatriotic. Beyoncé, who controls the direction of her career in a way that pioneering black women entertainers could not, has nonetheless styled herself in ways that recall the distinct racial history of the Creole South. Griffin considers how Michelle Obama's and Beyoncé's use of their respective family histories and ancestry has bolstered or diminished their popular appeal.

Perceiving is the process by which evanescent sensations are linked to environmental cause and made enduring and coherent through the assignment of meaning, utility, and value. Fundamental to this process is the establishment of associations over space and time between sensory events and other sources of information. These associations provide the context needed to resolve the inherent ambiguity of sensations. Recent studies have explored the neuronal bases of contextual influences on perception. These studies have revealed systems in the brain through which context converts neuronal codes for sensory events into neuronal representations that underlie perceptual experience. This work sheds light on the cellular processes by which associations are learned and how memory retrieval impacts the processing of sensory information. Collectively, these findings suggest that perception is the consequence of a critical neuronal computation in which contextual information is used to transform incoming signals from a sensory-based to a scene-based representation.

Population aging in the United States poses challenges to societal institutions while simultaneously creating opportunities to build a more resilient, successful, and cohesive society. Work organization and labor-force participation are central to both the opportunities and challenges posed by our aging society. We argue that expectations about old age have not sufficiently adapted to the reality of aging today. Our institutions need more adaptation in order to successfully face the consequences of demographic change. Although this adaptation needs to focus especially on work patterns among the "younger elderly," our society has to change its general attitudes toward work organization and labor-force participation, which will have implications for education and health care. We also show that work's beneficial effects on well-being in older ages are often neglected, while the idea that older workers displace younger workers is a misconception emerging from the "lump of labor" fallacy. We conclude, therefore, that working at older ages can lead to better quality of life for older people and to a more productive and resilient society overall.

The Hispanic population aged sixty-five and over - the most socioeconomically disadvantaged subset of America's elderly - is projected to quintuple between 2012 and 2050. While current longevity patterns for Hispanics relative to whites are favorable, old-age functioning and disability patterns for Hispanics are unfavorable and have serious implications for caregivers; families; and local, state, and federal governments. Troubling signs for the future Hispanic population (which are shared to varying degrees with other vulnerable groups) include the unresolved legal status of unauthorized immigrants, continued low levels of insurance coverage even after health care reform, some unfavorable trends in health behaviors, and continued disadvantages in educational attainment and income relative to whites. We urge policy-makers to deal with these potentially problematic health and well-being issues. Not doing so could have detrimental consequences for the future of the Hispanic population as well as other at-risk groups and, by extension, the U.S. elderly population as a whole.

Sleep occupies roughly one-third of our lives, yet the scientific community is still not entirely clear on its purpose or function. Existing data point most strongly to its role in memory and homeostasis: that sleep helps maintain basic brain functioning via a homeostatic mechanism that loosens connections between overworked synapses, and that sleep helps consolidate and re-form important memories. In this review, we will summarize these theories, but also focus on substantial new information regarding the relation of electrical brain rhythms to sleep. In particular, while REM sleep may contribute to the homeostatic weakening of overactive synapses, a prominent and transient oscillatory rhythm called "sharp-wave ripple" seems to allow for consolidation of behaviorally relevant memories across many structures of the brain. We propose that a theory of sleep involving the division of labor between two states of sleep-REM and non-REM, the latter of which has an abundance of ripple electrical activity-might allow for a fusion of the two main sleep theories. This theory then postulates that sleep performs a combination of consolidation and homeostasis that promotes optimal knowledge retention as well as optimal waking brain function.

Nearly all of today's confident dismissals of the notion of a "post-racial" America address the simple question, "Are we beyond racism or not?" But most of the writers who have used the terms post-racial or post-ethnic sympathetically have explored other questions: What is the significance of the blurring of ethnoracial lines through cross-group marriage and reproduction? How should we interpret the relatively greater ability of immigrant blacks as compared to standard "African Americans" to overcome racist barriers? What do we make of increasing evidence that economic and educational conditions prior to immigration are more powerful determinants than "race" in affecting the destiny of population groups that have immigrated to the United States in recent decades? Rather than calling constant attention to the undoubted reality of racism, this essay asks scholars and anti-racist intellectuals more generally to think beyond "the problem of the color line" in order to focus on "the problem of solidarity." The essay argues that the most easily answered questions are not those that most demand our attention.

How does the newly arrived immigrant respond to the news that an identity already awaits him? How does an African American hip-hop artist translate his struggles and triumphs across oceanic divides? What significance do American demographic shifts have in a global context? Hsu's essay examines what happens once individuals or identities migrate beyond the contexts that first produced them. He explores a variety of circuits: the satellite communities of Asian immigrant students who arrived on American university campuses in the late 1960s; enduring debates about a "post-city" identity, spurred by advances in cheap, efficient, world-shrinking communication technologies; and the new affinities and categories of self-identification made possible by a present-day culture that prizes interactivity and participation.

This interdisciplinary essay explores a fundamental paradox at the heart of American race relations since the 1960s: "the changing same." The more things change; the more they remain the same. Combining historical and social-scientific evidence with autobiographical reflections, this discussion critically probes the paradoxical decline and persistence of two dimensions of our enduring racial quagmire: racial inequality and white supremacy. The essay argues that these powerful and interrelated elements of America's continuing racial dilemma demand a massive democratic movement to alleviate both at once. This wide-ranging struggle to realize the promise of American democracy requires more than just a revitalized African American Freedom Struggle that is both intraracial and interracial. Progress toward resolving the seemingly intractable problem of racial inequality in the United States demands far more than intensified efforts to alleviate economic inequality; it requires alleviating white supremacy as well.

This essay explores come of the reasons for the continuing power of racial categorization in our era, and thus offers some friendly amendments to the more optimistic renderings of the term post-racial. Focusing mainly on the relationship between black and white Americans, it argues that the widespread embrace of universal values of freedom and equality, which most regard as antidotes to racial exclusion, actually reinforce it. The internal logic of these categories requires the construction of the "other." In America, where freedom and equality still stand at the contested center of collective identity, a history of racial oppression informs the very meaning of these terms. Thus the irony: much of the effort exerted to transcend race tends to fuel continuing division.

This essay examines the intertwined nature of seemingly neutral immigration laws that illegalize certain immigrant groups and the socially constructed attitudes and stereotypes that associate the same legally targeted groups with "illegality," to produce the racialization of illegality. These complementary factors are further sustained by other social forces, including media discourses that reify those associations. The racialization of illegality is a fundamentally situational, relational, dynamic, and historically and context-specific process. Today, Latino groups are the preeminent target group of both the social and the legal production of illegality. Thus, this essay examines Latinos' racialized illegality across geographical contexts, within their group, and in relation to other contemporary immigrants. Although expressions of racialized illegality and specific targeted groups will vary across time and space, the contours of the phenomenon will be present across contexts and times (and produce specific outcomes) because they are shaped by existing racial hierarchies.