Humans

How divorce hurts kids
Parents’ breakups take a selective toll on kids. Young children experience math and social problems after their parents begin the divorce process but not before, even if parents previously fought a lot, says sociology graduate student Hyun Sik Kim of the University of Wisconsin–Madison. Children of divorce also tend to struggle with anxiety, loneliness, low self-esteem and sadness, Kim reports in the June American Sociological Review. But reading scores and problem behaviors such as fighting remain stable after parents divorce. Data come from children tracked from kindergarten through fifth grade, with divorces occurring between first and third grade. —Bruce Bower

Teaching to achieve
So much for class lectures. Instructional methods that emphasize daily and weekly practice at problem-solving and data analysis boost college students’ performance in introductory biology classes, especially among those from poor backgrounds who often struggle in such courses, researchers report in the June 3 Science. A highly structured course design that included peer instruction and peer-graded practice exams, but no instructor lectures, generally yielded a better grasp of biology and higher grades for all students, relative to courses grounded in lectures and small-group exercises, say biologist David Haak of the University Washington in Seattle and his colleagues. —Bruce Bower

Human migration and climate change
Waves of settlers appeared and vanished as temperatures in western Greenland changed, suggesting a close link between human migration and climate change. Researchers led by William D’Andrea of Brown University in Providence studied temperature records in sediments drilled from two lakes in West Greenland. The area’s first settlers, the Saqqaq culture, arrived in a warm period 4,500 years ago and left during a chilly spell 1,700 years later — to be replaced by the Dorset culture, better adapted to hunting on sea ice. The work was published online in the Proceedings of the National Academy of Sciences on May 31. —Alexandra Witze

Tempest in the trees
Explorers Meriwether Lewis and William Clark ran into one of the worst gales in two centuries shortly after arriving on the Pacific Northwest coast, researchers have found. In November 1805, Lewis and Clark complained about a “perfect storm” that blew down trees all around them. By studying tree rings from Sitka spruce trees that made it through the tempest, scientists found that it was probably the most severe windstorm in the region for the past 200 years. Paul Knapp of the University of North Carolina at Greensboro and Keith Hadley of Portland State University in Oregon describe the storm in the June issue of The Holocene. —Alexandra Witze