Letters from the August 5, 2006, issue of Science News

Rod is the spoiler

While I applaud the work that is looking at the biochemical correlates of aggressive and delinquent behavior, it is important to emphasize that environmental factors still predominate when we are searching for the roots of violence (“Violent Developments: Disruptive kids grow into their behavior,” SN: 5/27/06, p. 328). Although there is no single factor underlying aggressive behavior in children, my own 30-plus years looking into the relationship between excessive parental discipline and delinquency has convinced me that the violent, recidivist, male juvenile delinquent who was not raised on the belt, board, cord, or fist is nonexistent.

Ralph S. Welsh
Danbury, Conn.

Odd shape

When I looked at the photo for “As waters part, polygons appear” (SN: 6/3/06, p. 348), I didn’t see a “pentagonal shape” in the swirling water. I saw a sine wave, wrapped around a circle. I was immediately reminded of the Bohr–de Broglie model of electron orbits forming standing waves. Rather than swirling water and glycol forming “unexplained” polygons, isn’t this simply a standing-wave phenomenon?

Ellery Frahm
Minneapolis, Minn.

Combinations of circles and standing sine waves might explain the observed shapes, agrees Tomas Bohr of the Technical University of Denmark. But his team has been unable to use the circle–sine wave model to explain how shapes vary as experimental parameters change.—P. Weiss

Rash statements?

It’s big news that poison ivy thrives where there are higher concentrations of carbon dioxide (“Pumped-up Poison Ivy: Carbon dioxide boosts plant’s size, toxicity,” SN: 6/3/06, p. 339)? Did everyone forget elementary school science and plant life’s dependence upon carbon dioxide? Do I advocate buying and driving the most carbon dioxide–emitting vehicle you can find? No. I guess I would just like to see more common sense and less common scare in your article.

Scott Billingsley
San Antonio, Texas

Poison ivy in enhanced carbon dioxide didn’t just grow. It grew much more than woody plants did under the same conditions. That difference between a weedy vine and woody plants could mean changes in the forest communities of the future.—S. Milius

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