In “Welcome to Everybody's Issue” [From the Editor], editor in chief Mariette DiChristina invites ideas to increase gender equality at Scientific American. Below her editorial is a list of the 42 members of the magazine's board of advisers, of which six are women. Adding more women scientific leaders to the board seems advisable if the aim is gender parity.

SHANA AELONY via e-mail

THE EDITORS REPLY: We agree, and we promise to do better.


“When Sex and Gender Collide,” by Kristina R. Olson, discusses children who choose to change gender. From age six until about 16, I wanted to be a boy. I played almost exclusively with boys, was a “tomboy,” hated anything “girly” and found girls rather silly. My thinking, to this day, is much closer aligned with the masculine world, but I am definitely a woman, happily married to a man. There is no way a child has the maturity to make the drastic decision to start taking medication to change sex.

ELSA HUNTLEY Vancouver, B.C.

OLSON REPLIES: Huntley makes a useful point that, like Charlie in my story, many children who defy sex-based stereotypes are not transgender. She also raises concerns about children “taking medication.” The article and my research are focused on early social transitions, which do not involve medical intervention. Instead they include changing one's pronoun and first name. As a researcher who is not a clinician, I do not advocate for or against any intervention. Rather, given that some children undergo social transitions, I study them to learn about gender and well-being. My hope is that one day we will use such research to determine which children are likely to grow up to identify as cisgender or transgender adults—and to then clarify which interventions maximize their well-being.


“A Moth's Eye,” by Morgen Peck [Advances], reports on research by Shin-Tson Wu of the University of Central Florida and his colleagues on replicating the surface properties of the titular organ to reduce glare on cell-phone screens. Think of the benefit if this technology were used to increase the practical efficiency of solar panels.

Also, the moth's eye uses raised bumps to achieve the desired effect, whereas the researchers produced it using dimples. Have they looked into cleanability with this approach? Such pits may trap dirt.

ALEX SMITH Littleton, Mass.

WU REPLIES: The antireflective coatings have actually already been used in solar cells, and they do indeed help improve energy-harvesting efficiency.

One reason we chose dimples is that they are simpler for mass production. The bump geometry is easier to clean, but because of a special coating, our film exhibits a self-cleaning effect, similar to a lotus leaf.


In “Postmodernism vs. Science” [Skeptic], Michael Shermer associates recent strife on campuses with so-called “postmodern professors,” falsely claiming they teach “that there is no truth, that science and empirical facts are tools of oppression by the white patriarchy.” It is ironic that a top science magazine would publish an article about an area of scholarship in which the author holds no expertise and that decries scientific knowledge denial while denying knowledge produced in other fields.

Scholars in many fields, including natural scientists, have shown that science has sometimes been used to justify oppression and inequality and that the institution is still struggling with sexism, racism and classism. But they have also explored how it has been central to destigmatization, liberation, progress and survival.

Countering knowledge denial, whether about climate or inequality, is an urgent, shared project. Perhaps Scientific American can join us in this endeavor?

CHARIS THOMPSON University of California, Berkeley


“Beyond XX and XY,” by Amanda Montañez, contributes to intersex visibility by showing that variations from what we typically think of as male or female are natural and numerous. There is just one thing we wish it had shown intersex is not: in need of “fixing.” The flowchart indicates where surgeries can “modify” the genitals and remove the gonads of children with certain diagnoses but does not point out the serious consequences. A “feminizing” genitoplasty can cause scarring, chronic pain and permanent loss of sexual sensation, and gonadectomy results in sterilization.

Montañez also neglects to note that raising a child as a boy or girl does not require surgery. Children's gender identity may not match the one they were raised with, and it should not be irreversibly enforced.

KIMBERLY ZIESELMAN Executive director, interACT: Advocates for Intersex Youth

MONTAÑEZ REPLIES: The graphic presents only the science of sex and gender as a spectrum, and its scope did not allow for addressing potential health impacts. I included surgery as an optional way a person might shift along that spectrum because many do undergo such procedures. The ways intersex and transgender or nonbinary identities might overlap is another area in which the graphic represents an incomplete picture of a very complex topic.


The graph “A Labor U-Turn” in “Women's Work,” by Ana L. Revenga and Ana Maria Munoz Boudet, claims to show a link between female labor force participation and countries' per capita GDP with a parabola. I believe it is mathematically unsound. If instead of highlighting a few data points very close to the fitted curve, we colored all of them the same shade, what remained would look like a dart board. I'm also surprised no countries are given with lower than 46 percent female participation.

THOMAS A. CONNER Mountain View, Calif.

THE AUTHORS REPLY: The U curve shows a nonparametric regression of labor force participation. It represents predicted values and is based on publicly available data from the International Labor Organization and the World Bank. Details on the methodology and similar results have been documented in a vast array of papers, including those by economists Claudia Goldin in 1995 and Kristin Mammen and Christina Paxson in 2000. The highlighted dots are only included as an example of different countries along the U curve. And the Y axis is truncated for presentation purposes. There are indeed countries with female participation below the 50 percent line. The countries included or left out of the figure do not change the results.


Clara Moskowitz's review of Significant Figures, by Ian Stewart [Recommended], incorrectly referred to Chinese mathematician Liu Hui's third-century A.D. proof of the Pythagorean theorem occurring hundreds of years before Pythagoras' birth. Liu Hui proved the theory independently of Pythagoras but did not predate him.

In “Postmodernism vs. Science” [Skeptic], Michael Shermer wrote that students at Middlebury College “physically attacked” Charles Murray and Allison Stanger. A police investigation determined that several demonstrators against Murray came from outside the campus community. Although the attackers were not identified, Middlebury maintains they were not students.