Shopping standards shift with age
In When good moods go decisively bad” (SN: 6/16/12, p. 10), researchers assume that their 70-year-old study participants would be as interested as their 20-something counterparts in finding up to 40 prices on 60 products in an Internet shopping exercise. When the septuagenarians fail to choose the cheapest product, the researchers infer that the happy elderly may make poor decisions. Perhaps instead, the happy oldsters make a quick, acceptable decision rather than waste time making a marginally more perfect one.
Kevin Stevenson, Port Townsend, Wash.

Bettina von Helversen, one of the study researchers, responds that elderly volunteers reported more interest in getting good deals on the task than younger volunteers did, although there’s no guarantee that both groups were equally motivated by financial rewards. Older adults probably did favor good-enough decisions, but because they experienced more positive feelings than the younger group, not because of a lack of motivation, in her view. — Bruce Bower

Birds forage intelligently
Having been there, I recognized the map of Kerguelen Island in “Birds forage with fractal-like flight” (SN: 6/2/12, p. 12) and looked it up on Google Maps. The flight paths shown closely follow seafloor topography, with concentrations centered on readily identifiable subsurface features. As an ocean­ographer, I have casually observed that gooney birds like to accompany our ship the RV Argo, using the aerodynamics of the ship’s passage to soar effortlessly and feasting every time our messman empties meal waste. I suggest the birds behave in a much more well-informed manner, responsive to their local environment, than portrayed in the article.
Leandra Vicci, Silk Hope, N.C.