Hardly Black and White
InThe Social Psychology of Success,” by S. Alexander Haslam, Jessica Salvatore, Thomas Kessler and Stephen D. Reicher, it seems the authors’ bar graphs concerning blacks’ perceptions of inferiority are adding to problems inherent in group comparisons. The flat tops of the graphs on page 27 imply that all whites are smarter than all blacks. Each bar should actually be a compressed bell curve, showing that only a small percent of whites have superior intelligence and that many blacks are smarter than many whites.

Dan Robinson
Eugene, Ore.

Justified Prejudice?
Siri Carpenter’sBuried Prejudice” opens with a quote from Jesse Jackson about hearing a pedestrian’s footsteps behind him and feeling relief when he notices that his follower is white. The quote was a good opener, but it was quickly dropped without a thorough examination. Dinesh D’Souza’s book The End of Racism (Free Press, 1995) contains a deeper analysis, ending with a most pertinent point: “Given the crime rates of young black males, ‘the stereotype is not a stereotype any more,’ says Howard University education professor Kenneth Tollett. ‘A stereotype is an overgeneralization. The statements we have called stereotypes in the past have become true.’ ”

Accordingly, I found most interesting the views expressed in your article by Northwestern University psychologist Jennifer A. Richeson, who speculates that our brains may automatically give preferential attention to blacks as a category, just as they do for threatening animals such as snakes.

That idea will surely provoke a negative response from those who see prejudice on her part for likening young black men to snakes, but I see a perfect analogy: it is wise to fear what is dangerous. Thousands of people die every year from snakebites. Thousands are victims of the criminal acts of young black men, one out of four of whom have a criminal record. Is it prejudice to reason rationally and logically? It certainly has become politically incorrect.

Jeffry L. Smith
via e-mail

CARPENTER REPLIES: Many people find this line of reasoning persuasive, but it is incomplete. It is unfair to judge an individual based solely on his or her group membership, and such presumptions of guilt by association do not promote accuracy in decision making. For example, although blacks are arrested and incarcerated in disproportionate numbers, the majority of people of all races are law-abiding citizens. To assume that a randomly chosen black person is probably a criminal would be erroneous and unjust.

We all use statistical base rates to guide our decisions. For example, we use a person’s age and gender to set car insurance premiums, and we usually include only women in breast cancer research, even though men can develop the disease. But this statistical reasoning has both costs and benefits. Before deploying a stereotype to judge another person, we need to weigh the trade-offs. What do whites gain if we assume black men are dangerous? What do we as a society—not to mention innocent black men—lose when we’re wrong? As work on implicit bias shows, the presence of stereotypes of which we may not be aware means that we are in the unhappy position of relying on stereotypes even when we don’t want to.

A Poor Choice
I wonder why you used a picture of Senator Barack Obama in Kurt Kleiner’s article “In Your Face” [Head Lines]. The article rightly reveals that the “shouting heads” of television news affect our views partly because of the extreme close-up position of the cameras. But why didn’t you use a picture of one of the actual confrontational political commentators? Bill O’Reilly, perhaps?

The editors should take a moment to read the opening statement of Siri Carpenter’s excellent article: “Deep within our subconscious, all of us harbor biases that we consciously abhor. And the worst part is: we act on them.” You managed to demonstrate how an implicit racial bias, “black people are loud and angry,” can become an explicit choice. Obama may have many character traits that affect his likability. I do not think, however, anyone can characterize him as loud, angry and rude.

Ra’ayah Turnbull
Brooklyn, N.Y.

Flying High
R. Douglas Fields’sBrain Cells Into Thin Air” [Perspectives] is most interesting when you consider that a pressurized aircraft cabin is standardized to 8,000 feet (2,440 meters). Passengers are taken to that altitude rather quickly.

“harriev”
adapted from a comment at www.SciAm.com

FIELDS REPLIES: The dangers of hypoxia in aviation are well known, and in many situations they are not subtle.

Healthy individuals on a normal commercial flight will experience a significant decrease in blood oxygen, according to a 2006 study in the journal Aviation, Space and Environmental Medicine. A 2004 study in the same journal found that the amount of oxygen decreases in proportion to a person’s age, but in 2002 other researchers
had reported in Pediatric Emergency Care that children also experience effects of hypoxia, including an increased heart rate.

People with preexisting conditions are at risk for serious injury when they fly. In 2006 Ludvic Zrinzo and his colleagues reported two relevant cases in the Journal of Neurosurgery. A 22-year-old man, who was fine until he flew, returned from a flight with a headache, which quickly developed into severe neurological problems that resulted in a coma. The second case concerned a 55-year-old woman who was also well until she flew. She suffered such severe brain injury from a commercial airline flight that she died 24 hours later.

As in climbing, the standards for airline safety are focused on preventing sudden illness. No one gets a brain scan if he or she does not feel sick. Yet only one of 13 Everest climbers return from the summit with a normal brain scan. There is one crucial difference between climbing and flying, however: nobody can change the air pressure on a mountaintop. Why are we flying around hypoxic at 8,000 feet?

Editors’ note: Fields’s original, longer comment—and his responses to many other hypoxia-related queries—can be found here.

The Stress Factor
I enjoyed Melinda Wenner’s article, “Infected with Insanity.” I was a bit disappointed, however, that she made no mention of the role of stress and its influence on influenza infection and immune system function. Yes, microbes may have an effect on the developing brain, but what about the stressed-out soon-to-be mother?

I find it amusing that prescription drugs are promoted as a possible solution when something much more fundamental may be at fault—how well the expectant mother is able to cope with stress. If that ability plays a role, perhaps mothers’ coping skills could be developed, reducing the risk of low immune function and avoiding adverse side effects altogether.

William Lu
via e-mail

WENNER REPLIES: Lu is correct. A number of studies suggest that maternal stress can affect the development of fetal neurons and influence a child’s behavior and mental health. Christopher Coe, the University of Wisconsin–Madison psychologist whose work on prenatal infections I mentioned in my article, also studies how stress affects fetal development. An overview of related research can be found in Perinatal Programming: Early Life Determinants of Adult Health & Disease (Informa Healthcare, 2005), a book Coe co-edited with University of Newcastle psychologist Deborah Hodgson.