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Why a grizzly gets you shivering—but not global warming

In my Science Confirms the Obvious post today, I discussed the first psychological proof (so say the authors) that humans can indeed experience emotions without immediately knowing why. We do this, they say, because we evolved that way. True, scientists love that explanation, but here it’s quite intriguing.

Say you’re walking through the woods and encounter a grizzly bear. You see it and freeze that instant—even before your stomach drops with fear. “After all, you are likely to live longer if you immediately stop moving at the sight of a growling grizzly bear,� write researchers Kirsten Ruys and Diederik Stapel of The Netherlands’ Tilburg University, “and do not need full awareness for such a response to be instigated.� Given the flood of unexpected stimuli we face moment to moment, quick reactions make sense for survival.

You, that bear, and other animals experience emotions such as fear, anger, or disgust. But only a few species are aware of their emotions. This ability helps humans judge and respond to the behavior of others in order to navigate social situations and, ultimately, grease the wheels of complex society.

The study got me thinking about a talk given by Harvard psychologist Dan Gilbert at last October’s Pop!Tech conference. He expounded on why humans are so savvy at grasping immediate threats like grizzly bears or baseballs hurtling at our heads but suck at grasping abstract, slowly approaching ones like global warming. According to Gilbert, a “very large part� of our brains is devoted to dealing with immediate threats, but a “very small part� is concerned about planning for the future.

Humans, apparently, are still in the early stages of evolving extended response mechanisms. But it seems likely that by the time we portion more of our brain to long-term dangers, there will be few grizzly bears around to worry about, and a whole lotta global warming.

Copy editors, taxonomists, and Speed Racer tussle over a species’ humanity.

I’ve been thinking about chimps lately. I called them a “who� and not a “which� in a recent piece I produced for the American Museum of Natural History. This earned me a virtual slap by my copy editor. As in:

“Chimpanzees, who WHICH are not bipedal…�

I was just giving a nod to a fellow hominid—the taxonomic group that includes chimpanzees, gorillas, orangutans, and humans. Pan troglodytes are 99.8% genetically similar to us, making them our closest living relative. But “who� is a pronoun reserved for people.* Chimpanzees are not, taxonomically speaking, people. If they were in fact bipedal, they would have been inducted to the hominid subgroup Hominina (hominins for short), which includes all the who-like things that walked about after chimps and humans diverged 6 million years ago.

A recent PETA press release has further strengthened my instinct to view chimpanzees as the brethren they are. The animal-rights group alleges that during the production of the upcoming Speed Racer movie, some person or persons on set abused the chimpanzee that plays Chim-Chim, the Racer family pet. As posted on an Arizona Daily Star film blog:

Unfortunately, in spite of PETA’s request to leave real animals out of the film, the Wachowski brothers chose to use a live chimpanzee to play the role of Chim Chim . . . While filming in Germany, a whistleblower contacted PETA alleging that one of the two chimpanzees used in Speed Racer was severely beaten. The beating was said to have taken place out of the view of the cast and crew. PETA also confirmed the whistleblower’s report that a chimpanzee suddenly attacked and bit a young actor.

If this incident is true, is it any surprise that “Chim Chim� defended itself? It’s a nondomesticated animal, and one which (who?) probably doesn’t appreciate being squashed into the trunk of a Mach 5.

Chimpanzees are also endangered. Yet it’s legal in 44 U.S. states to own them as pets and use them as actors or photo props. Their ubiquity in ads and movies leads people to assume they’re not imperiled. Read a recent letter about this issue in Science by several researchers, Jane Goodall among them, who entreat scientific organizations to work together to shift “the perception of chimpanzees as frivolous subhumans that are not in danger of extinction to more scientifically accurate characterizations of our closest relatives that stir interest, respect, and conservation efforts.�

This goes well beyond a simple case of anthropomorphizing. In all these instances, there’s a tug-of-war ensuing in the gray area between “us and them.� Either we’re attributing too much humanity to chimps, or not enough. We too infrequently recognize them as sentient beings that suffer if smuggled from their home or abused. But some people go so far as to think this dwindling wild animal has a place in our domestic lives.

Perhaps this is also a reminder to acknowledge the animal-nature of humans. It stumps me why some animal encyclopedias, such National Geographic’s “Animals� site or the University of Michigan Museum of Zoology’s award-winning natural history database Animal Diversity Web, has no descriptive information for Homo sapiens, unlike Pan troglodytes and all the others.

When you make the rules, I suppose, you don’t have to explain why you’re the exception. Or why your closest relatives can’t cop a little respect.

* Might I add, incidentally, that people refer to their cats, dogs, and other domesticated pets as a “who.� Try it; you won’t be able to help it.

Census study reveals sex selection also happens in U.S.

In many Asian countries, the cultural preference for boys is resulting in lopsided sex ratios. To those who assume there’s no prenatal sex discrimination in the United States, think again. The first published analysis of its kind, which appears in the latest issue of the Proceedings of the National Academy of Sciences, reveals that some—but not most—Asian families in America are choosing to have a son after one or more daughters.

The natural sex ratio is 1.05 boys for every girl born. This ratio held up for the first (U.S.-born) child of residents who indicated they are Chinese, Korean, or Asian Indian on the 2000 Census. But if their first child was a girl, the sex ratio of the second child was 1.17:1. If the first two children were girls, that ratio jumped to 1.51:1. (Compare to the most recent data for India: 1.39:1 and China: 2.25:1.)

Interestingly, the imbalance seems to be a growing trend here. The researchers found that sex ratios among Asians the 1990 U.S. Census were much more equivalent. I asked the study authors, Lena Edlund and Douglas Almond of Columbia University, why. Their e-mail response:

We don’t know. Part may be compositional given substantial immigration during the 1990s (i.e. populations are different). This also provides more statistical power to detect effect in the 2000 Census (the sample is larger).

Also, prenatal ultrasound was not usually done in the 1980s, but became the norm during the 1990s. And between 1989 and 1999, ultrasound use among the Asian groups considered rose faster than it did for whites (as indicated by NCHS natality micro-data).

Moreover, the availability and quality of prenatal sex determination may have improved. The imaging may be better and there are clinics actively advertising their services. (One website we’ve seen claims to be able to do it reliably already at the 12th week.)

The researchers conceded that it’s hard to predict where this trend will go in the future. Their new data may be implemented by health care practitioners to help curb the practice. And subsequent generations of the sampled families in the 2000 Census will likely show less proclivity for boys as assimilation dampens cultural preferences.

The trend is not, however, swaying the overall ratio of men to women in the United States—the population of Indians, Chinese, and Koreans is simply too small (< 2 percent) to be a significant factor.