Citations: Susan Levine, Wen-Hsiung Li and Ying Tan, National Opinion Research Center, Robert Sampson, Allen R. Sanderson, Paul Sereno

Block by block
A U of C study of 288 children ages four through seven found that by age four and a half, boys are better than girls at putting together complex shapes. Reported in the July 1999 issue of Developmental Psychology, the study, led by psychology professor Susan Levine, offers the first unambiguous evidence that such differences, once thought to develop during adolescence, begin much earlier. The origin of the differences, says Levine, remains unclear: “They could be related to the way children are reared, caused by biological factors, or both.” Enriched learning environments, she says, will help girls develop high levels of spatial skills, needed more and more in a technology-driven society.

Color-coded
Ecology & evolution professor Wen-Hsiung Li and research associate Ying Tan reported in the November 4 Science that full-color vision originated in a primate suborder about 55 million years ago--not in higher primates 15 to 20 million years later, as had been thought. Analyzing genes from tissue samples from 20 different kinds of prosimians, mostly lemurs, Li and Tan discovered a polymorphism--a gene variation that codes for protein pigments in the retina that produce full-color vision in primates--in two diurnal species and one nocturnal species. Because color vision is useful only in daylight, Li was not surprised to find the polymorphism in the diurnal prosimians. The polymorphism in the one nocturnal species adds weight to the theory that nocturnal species originally evolved from diurnal prosimians.

A new family portrait
The American family no longer looks the way it did three decades ago, according to a new report from the National Opinion Research Center. The report says the number of children living with their original two parents has decreased from 73 percent to 51.7 percent since 1972. That year, in only 33 percent of families did both parents hold a job, while in 1998, the number had risen to 67 percent. Unmarried people with no children now constitute the most common living arrangement in the country.

New window into crime
There might be less of a connection between a neighborhood’s appearance and its crime rate--the “broken windows” theory--than previously thought, says a major study of Chicago neighborhoods by sociology professor Robert Sampson. The study, published in the November issue of the American Journal of Sociology, argues that concentrated poverty and low “collective efficacy,” or the capacity of neighbors to work together to strengthen their community, play a greater role in predatory crime than the neighborhood’s appearance.

More women Ph.D.'s means more Ph.D.'s
An increase in the number of women seeking graduate education has caused U.S. universities to award a record number of Ph.D. degrees, says a federal agency report prepared by National Opinion Research Center senior research scientist Allen R. Sanderson, AM’70. The number of women receiving Ph.D.’s rose 20 percent from 1992 to 1997 and has increased seven-fold since 1967.

A dinosaur among dinosaurs
Organismal biology & anatomy professor Paul Sereno and his team have discovered another dinosaur species in the African Sahara: Jobaria tiguidensis. Described in the November 12 Science, the species, with 95 percent of its skeleton preserved, is the most complete long-necked dinosaur discovered from the Cretaceous Period. Named for “Jobar,” a creature in local legends, and a cliff near the excavation sites in the Republic of Niger, Jobaria tiguidensis doesn’t fit the typical sauropod image. With its spoon-shaped teeth, relatively short neck, and simple backbone and tail, the species is proof of the uneven pace of skeletal change--a dinosaur that changed very little over millions of years.--M.R.Y and Q.J.