Wednesday, April 20, 2011

Women Think Venus Is Funny; Men Prefer Mars

Gender Differences in How We Process Humor

Functional MRI images have shown gender differences in emotion processing, and behavioral studies have found gender differences in humor processing. In "Gender Differences in the Neural Correlates of Humor Processing: Implications for Different Processing Modes" (in the April issue of Neuropsychologia) an international team of investigators report on an experiment assessing the reactions of 14 females and 15 males to cartoons. Blood oxygenation levels were assessed alongside fMRIs. Women, it seems, process humor primarily in the part of the cortical processing system associated with primitive emotions and motivations. While men, too, engage those deep brain structures, more than women they also engage parts of the cortex associated with evaluative thinking.

Tuesday, April 05, 2011

Which Came First, the Tool or the Hand Size?

Did Technology Drive Human Evolution?

140 years ago Charles Darwin speculated that tool use may have influenced the evolution of the human hand. Now, in "Technology Based Evolution? A Biometric Test of the Effects of Handsize Versus Tool Form on Efficiency in an Experimental Cutting Task," in-press at the Journal of Archeological Science, two anthropologists at the University of Kent in Canterbury are investigating the particulars of that idea. Through a series of experiments with stone flake tools (similar to the those used by African hominids 2.6 million years ago) and un-handled steel blades, they have shown that bigger hands use those tools more efficiently. The scientists speculate that just as opposable thumbs may have enabled tool use, tool use may have influenced the biological evolution of hand size—and of musculature and bone structure in the hand. As eons ticked on, it was the hominids with genes coding for hands adept at tool use that survived.

Saturday, April 02, 2011

In Scientific American This Month: Outsmarting Dengue Fever

In April's Scientific American

Just after sunrise in early January, a delivery van trundled along a suburban street in Queensland, Australia. Inside were tubs filled with a type of mosquito that carries dengue fever, the flu-like illness that annually sickens 50 million to 100 million people worldwide. Workers inside the van stopped at every fourth house, took out what resembled a small Chinese food container and released 40 mosquitoes into the wild. After a week, they had filled the air with 6,000 insects. By early March they had launched 72,000....

Read the article.