Now Fear This
Regarding Steven Johnson's article "The Brain and Emotions: Fear" [March]: It is the height of arrogance for us to assume the amygdala is obsolete as an adaptive mechanism. The amygdala and its lightning-fast capabilities are most likely far more relevant to this world than Johnson's article credits. The amygdala is appropriately overbuilt, just as a freeway should be in an earthquake zone, because survival is the ultimate exigency. Being overbuilt, the mechanism saves us but leaves a residual of its process in our physiology. This residual can gradually be removed through therapy that embraces deep grieving—a uniquely human adaptation—as one of its components. More study is called for before we muck up what evolution has designed quite brilliantly, thank you!
San Luis Obispo, California
Care to Spare
Sarah Hrdy's political agenda of publicly subsidized day care is not supported by her research ["The Hardy Sarah Blaffer Hrdy," March]. She operates from a premise that primate mothers depend on support systems to raise their young successfully. But the "allomother system" she observed bears little resemblance to our modern day-care system. Public day-care providers are not relatives, nor does the structure of day care mimic that of infant care in a primate troop. That Sarah Hrdy uses her research to claim some kind of authority in the day-care debate is a wanton extrapolation of her findings.
Temple, New Hampshire
The article on Sarah Blaffer Hrdy and her concept of motherhood was fascinating. I cannot agree more with Hrdy's belief that many women approach motherhood with ambivalence. We have a solution that involves allomothers. My husband and I were living with another couple to save expenses in the late 1970s. We were comfortable with the situation, and when my friend became pregnant, we saw no reason to change anything. It is now 25 years later, and we have between us four healthy sons, although both my friend and I have remarried. Having a spare mom around for nursing, baby-sitting, making dinner, doing laundry, doctor's visits, and taking over when you were fed up with the kids was priceless.
Sharon Ferraro, Pat McCarthy
Thank you for the article on research into the medical use of mescaline and other hallucinogenic drugs ["Peyote on the Brain," February]. It's good to see science moving forward in spite of the prevalent drug-war dogma. Sufferers of cluster headaches have found that indole-ring hallucinogens—particularly LSD and psilocybin/psilocin—promise to be effective treatments. So far, the evidence is informal and anecdotal, but the success rate is high. Formal research is needed to determine optimum dosages, side effects, and interactions with other drugs.
Season in the Sun
I'm curious why the article "Season of Fire" [February] didn't mention proximity to the sun as a factor influencing the frequency of volcanic eruptions in winter. Earth is closest to the sun in winter, so the tidal forces from the sun would be strongest at that time. Or would those forces be insignificant compared with the ones mentioned in the article?
Volcanologist Ben Mason responds: The gravitational attraction of the sun and the moon to Earth causes ocean tides and deformations of the Earth known as Earth tides. Some scientists have claimed that Earth tides can trigger eruptive activity. While Earth tides and lunar tides could have caused the periodicity of some individual volcanoes, there is no statistical significance between these tides and the eruption data set I studied.
In "Home Remedy for Earth" [March], a photo caption incorrectly identified lichens as "symbiotic arrangements of bacteria and algae." Lichens are associations of fungi and algae.