White (but Not Black) Americans Continue to See Racism as a Zero-Sum Game; White Conservatives (but Not Moderates or Liberals) See Themselves as Losing.

In a 2011 article in this journal entitled "Whites See Racism as a Zero-Sum Game That They Are Now Losing" (, 215-218), Norton and Sommers assessed Black and White Americans' perceptions of anti-Black and anti-White bias across the previous 6 decades-from the 1950s to the 2000s. They presented two key findings: White (but not Black) respondents perceived decreases in anti-Black bias to be associated with increases in anti-White bias, signaling the perception that racism is a zero-sum game; White respondents rated anti-White bias as more pronounced than anti-Black bias in the 2000s, signaling the perception that they were losing the zero-sum game. We collected new data to examine whether the key findings would be evident nearly a decade later and whether political ideology would moderate perceptions.

Range-frequency effects can explain and eliminate prevalence-induced concept change.

Why would concepts seem to grow when their instances become rare? Human observers can respond to decreases in stimulus prevalence by expanding their conceptual boundaries of those stimuli. This prevalence-induced concept change may have serious social consequences, since many real-world detection tasks demand consistent judgments over time. The current work aims to identify the computational process that produces prevalence-induced concept change.

Tips From the Top: Do the Best Performers Really Give the Best Advice?

Everyone knows that if you want to learn how to do something, you should get advice from people who do it well. But is everyone right? In a series of studies ( = 8,693), adult participants played a game after receiving performance advice from previous participants. Although advice from the best-performing advisors was no more beneficial than advice from other advisors, participants believed that it had been-and they believed this despite the fact that they were told nothing about their advisors' performance.

Exposure to descriptions of traumatic events narrows one's concept of trauma.

The concept of "trauma" was originally used by psychiatrists to describe horrific events such as rape and torture that characteristically provoke extreme emotional distress. Both colloquially and clinically, the concept of psychological trauma has broadened considerably. Although many clinical scientists have expressed concern about the broadening of the concept of trauma, it remains unclear how this concept expansion occurs.

Feedback moderates the effect of prevalence on perceptual decisions.

How does the prevalence of a target influence how it is perceived and categorized? A substantial body of work, mostly in visual search, shows that a higher proportion of targets are missed when prevalence is low. This classic low prevalence effect (LPE) involves a shift to a more conservative decision criterion that makes it less likely that observers will call an ambiguous item a target. In contrast, Levari et al.

Prevalence-induced concept change in human judgment.

Why do some social problems seem so intractable? In a series of experiments, we show that people often respond to decreases in the prevalence of a stimulus by expanding their concept of it. When blue dots became rare, participants began to see purple dots as blue; when threatening faces became rare, participants began to see neutral faces as threatening; and when unethical requests became rare, participants began to see innocuous requests as unethical. This "prevalence-induced concept change" occurred even when participants were forewarned about it and even when they were instructed and paid to resist it.