Archive for March, 2013

“Men and Women Are From Earth”

There are myriad competing theories about just why men and women think and behave differently from each other. From the evolutionary, to the physical and chemical, to the social, explanations for gender differences in behavior, personality, and ability are nearly as varied as they are ubiquitous.

There’s just one problem: all too often, no one bothers to check if those differences actually exist first.

Countless pop-science articles and books (as well as numerous scientific studies) exist that purport to categorize, measure, or explain differences in the way that men and women view the world, react to stimuli, behave in relationships, and so on. The same sort of thinking is applied to works attempting to prove, justify or explain differences in male and female intellectual achievement, particularly in areas like science and mathematics. What I have for you today is some evidence, in the form of an analysis of a number of large datasets of personality traits, suggesting that all these articles, books and studies are putting the cart before the horse, and that most observed psychological differences between men and women are either much less marked than is commonly believed or show considerable overlap and cross-over between the sexes, pointing at causes much less fixed and immutable than many people would suggest.

Researchers at the University of Rochester analyzed data from 13 studies (comprising 13,301 individuals in total), and performed a variety of statistical analyses on each, attempting to determine whether any of the 122 indicators studied (and if so, which) formed such distinct groupings between male and female subjects that they could be used, either individually or in concert, to predict with a high degree of confidence whether a person was male or female – and by association, whether that person shared other such sex-linked traits with other members of their group.

The authors contrast their approach with one that notes an average difference between sexes (as is common in a lot of pop-science writing, among other things) and then attempts to explain it or treats it as an innate difference that distinguishes men and women. The latter approach is less useful because it masks some very common features of these sorts of datasets – the amount of overlap between groups and the amount of variation within each group, which can point at the differences being studied as much less significant than they are widely assumed to be.

To start, the researchers demonstrated the use of their analysis on datasets that would be largely noncontroversially accepted as broadly different between male and female subjects – size, physical strength, and “traditionally sex stereotyped” leisure activities, such as boxing and cosmetics. They showed that these variables could be used to accurately sort men and women into distinct groups, with very few cross-overs. This result, as the researchers note, is unsurprising – sex-based differences in size and physical strength are well-established, and the leisure activities used in the validation phase were selected for being overwhelmingly preferred by one gender over the other. However, the results demonstrate that their analyses are capable of finding sex-based differences in a given dataset.

Moving on to the meat of the analysis, however, the researchers took on a slew of other personality and behavioral attributes, grouped broadly into four categories:

  • Sexuality and Mating (comprised of data about sexual behavior, attitudes, and partner or mate selection)
  • Interpersonal Orientation (broken into two subsets related to empathy and relational interdependence)
  • Gender-Related Disposition (among other things, measures of masulinity, femininity, and inclination towards science), and
  • Intimacy (both with romantic partners and in non-romantic contexts, such as with a close friend)

They analyzed these sets of variables separately, and then all together, looking for evidence that they could be used to predict whether a given subject was male or female. And what they found, with a very few exceptions, was…nothing.

For all but a handful of the variables studied, the results showed that rather than displaying distinct psychological differences between men and women, each variable instead fell along a continuum, with considerable overlap between the sexes. Furthermore, they found that having an especially “male” or “female” score in one trait was not predictive of a subject scoring similarly in other traits. In other words, if you simply take the average of the sexes for each trait, you’ll find that men are more aggressive and women are more talkative – but finding that a given person is especially aggressive doesn’t let you predict how talkative they’ll be, or vice versa. This continuum of responses makes it less likely that the analyzed traits are sex-linked in a biological sense, also, since we’d expect them to be much more nearly universal within the sexes (as, for example, having breasts is among women, or facial hair among men) if they were.

This has implications for how we write characters of both sexes – because a character who falls into neatly delineated sex-based categories in all of their personality traits is not only likely to be less interesting than a more nuanced one, they’re also demonstrably unrealistic – and just as it makes for a better story when our characters’ physical worlds are well-developed and realistic, so, too, do we benefit when their inner worlds reflect the same kind of nuance.

Going underground

Science fiction may often focus on new planets, but we don’t even know much about our own. The Deep Carbon Observatory aims to change one not-so-small piece of our ignorance. The multidisciplinary group of scientists wants to better understand what happens to carbon deep inside the earth, including carbon caught up in living things. That’s right: there is life outside the thin zone that we think of as habitable.

The project is organized into four sections: Deep Carbon Reservoirs and Fluxes, Deep Life, Deep Energy, and Extreme Physics and Chemistry. Even their titles seem science-fictional.

I’m a biologist, so Deep Life is my favorite. The first guiding question for that section: “What’s down there?” How many science fiction tales have “What’s out/down/in/under there” as their guiding question?

Even the chemistry and physics are complicated. We can’t do experiments easily or at all because the temperature and pressure are hard to duplicate: Extreme Physics and Chemistry indeed, at pressures of hundreds of tons per square inch and 2500F.

Reservoirs and Fluxes has to do with movement of carbon into and out of the earth. Volcanoes, anyone? And plate tectonics, with chunks of crust sliding into the mantle and taking carbon with them. The deep carbon cycle operates on a huge scale, and we don’t know much about it.

Deep Energy is just as poorly understood. Our major energy sources are carbon compounds: oil and coal are fossil biological carbon. But it’s also possible that life isn’t needed to produce hydrocarbons, that these compounds are also formed in the deep crust or mantle.

Want to learn more? Living on Earth just interviewed DCO Executive Director Robert Hazen.

Dr. Hazen doesn’t talk about science fiction at all. But what do you think? Doesn’t this just spawn all sorts of science fictional ideas?

Using DNA to archive the past for the future

I’ve spent a lot of time over the last few months trying to pare down a quarter century’s worth of files, photos and ephemera. Among the many boxes of paper, I’ve found photos from my high school years, notes from forgotten projects, and correspondence with friends and family and colleagues, some of whom I haven’t seen in years. It’s been a lovely trip down memory lane.

But I also discovered ancient floppy disks with college term papers, Zip disks full of archived emails, and CD photo albums. At least that’s how they were labeled. I no longer have a computer that can read floppies and even some of CDs have become unreadable. Fortunately over the years I’ve transferred many of my files to new media, but some of the files may be forever unrecoverable. While DVDs and hard drives can hold a lot more information – and weigh a lot less – than a box of paper printouts, the fact is that my old paper files are more likely to be readable 30 years from now than the digital files currently residing on my laptop.

This, of course, presents a difficult problem not only for people like me who want to be able to access their photos and letters and personal documents in the future, but also for archivists, historians,  governments and other organizations who want and need to ensure that today’s digital data will remain accessible decades or centuries from now.

It turns out that a biochemical approach to information storage may be part the solution. Naturally occurring DNA molecules encode information that directs the synthesis of the tens of thousands of proteins and other molecules that make up a living cell, along with the processes that allow the development of complex multicellular organisms (such as us humans). The development of ever faster and more accurate methods of both synthesizing and determining the sequence of DNA molecules has not only improved our understanding of normal DNA function, but also spurred the creation new nucleic-acid based technologies.

Animation of a rotating DNA structure.One such biotechnological innovation is the development of methods that use the information storage properties of DNA to encode digital data. Just a few months ago EMBL molecular biologists Nick Goldman and Ewan Birney published a paper demonstrating that one gram of DNA can hold more than 2 million gigabits of information, or “468,000 DVDs”. They were even able to build in error correction to be sure the encoded information would be stored and read accurately. And if kept in a cool dry environment, DNA can potentially remain stable for tens of thousands of years, making long term archival storage possible.

Naturally there are drawbacks to using DNA as a storage medium. Once the data is written by synthesizing the DNA sequence it cannot be changed. And there is no easy way to retrieve just a small portion of data without sequencing a big chunk of DNA. There is no equivalent to the list of files on your hard drive to find the data you are looking for. It’s not at all practical for information you would want to frequently retrieve or modify, and synthesizing DNA takes longer (and is more expensive) that saving a file on a thumb drive.  But unlike DVDs, which will eventually seem as archaic as papyrus as a storage medium, we humans should be able to sequence DNA molecules and decode the information stored therein – assuming, of course, that human society retains at least at the level of technology that exists today.

And to get a bit more speculative, the  biochemical properties of DNA leave open the intriguing possibility that the encoding methodology could be used to insert important files directly into human genomes creating living data repositories. The method could also be used to mark one’s self as part of a group or organization through genetic engineering.

Of course that idea isn’t new to science fiction. In Chris Lawson’s 1999 short story “Written in Blood”, a Muslim man has part of the Koran encoded as DNA inserted into his genome. That decision turns out to be fatal when the inserted DNA creates a mutation that causes leukemia. His biochemist daughter eventually develops a better method of encoding and she uses it to write what’s important to her into her own blood: photos of her wedding and her family, Martin Luther King’s “I Have a Dream” speech, Watson and Crick double-helix paper, Shakespeare’s Julius Caesar and a Muslim parable. And a paraphrase of Einstein’s words after the atomic bombing of Japan, expressing hope in humanity:

“The release of atom power has changed everything but our way of thinking,” then added, “The solution of this problem lies in the heart of humankind.”

Birney and Goldman selected similar data to test their real-world system: a digital version of Shakespeare’s sonnets, a photo of their offices, a pdf of Watson and Crick’s paper with the structure of DNA, and an audio clip from Martin Luther King Jr.’s “I Have a Dream” speech. If we were to use the technology to create a time capsule for our descendants to open millennia from now, Shakespeare and MLK are obvious selections of cultural significance.

What we choose to archive from our past to share with future generations says a lot about what we value today. I’d hope that ultimately we would include data representing a diverse range of cultures and voices. It’s up to science fiction to ask the question of what future humans might make of the information.


Goldman et al. “Towards practical, high-capacity, low-maintenance storage in synthetic DNA” Nature (2013) doi:10.1038/nature11875


Rat Telepathy: Let There Be Nuance

The scientists developing rat telepathy have an aim. They want to answer the question: Can mammal brains be trained to communicate with each other electrically? Research shows that it can work in rats, at least. Much remains to be seen: Will it work in other mammals? In humans? For now, the electrical communication is one-way; is ‘telepathic’ repartee possible? Is it possible for different species to communicate effectively brain-to-brain?

We know from other research that some mammal brains can control machines designed for that purpose. But what about feedback – sensory information simulating touch transmitted from prosthetic to brain, for example? Current science seems to indicate it’s possible. It’s certainly an easy leap to make in fiction, but any scientist worth her weight in pipettes will tell you that it’s usually a few orders of magnitude harder to manage in real life.

Navigating the administrative and regulatory obstacle courses between the lab bench and the clinic alone is costly in terms of time and money, yes, but it also takes a toll on the heart. The business of science is hard on people. It consumes researchers in much the same way biologists burn through reagents, and at metaphorically the same rate. It’s dimensions harder for scientists who experiment on animals. Not only are the mountains of paperwork piled higher and the pitfalls dug deeper, the researchers are human. Animal lovers and vegans among their number.

How can anyone tolerate animal testing? For that matter, how can anyone eat meat? It’s all down to our capacity for cognitive dissonance. Hypocrites! Idealists!

It’s complicated. It’s hard and it should be. We should be suspicious of over-simplification, even in our own fiction. We should look close, listen carefully, and imagine with depth. In our writing, we should resist the ‘mad scientist’ trope. For a fun change of pace, avoid pursuing plot devices to their logical extremes. Instead of painting science as the villain, how about shining a light on the tensions that emerge when budget constraints – sequestration, anyone? – force post-docs to compete with their mentors for increasingly limited federal funds? Why not examine the consequences of alowing basic science to languish while throwing money at the few headline-making scientists so adroit at standing on giant shoulders that they achieve celebrity status? What happens to a civilization after a generation of quiet giants is lost?

And what of the tender-hearted scientist? She’s no fool. She would never release lab animals into the wild. Instead, her data is better because she stacks the deck in favor of her furry subjects. They have the best care possible under the circumstances, and it shows in how well her test results stand up to peer review. Her work informs others’ and ultimately, the care provided in her vivarium becomes one high standard to which others’ are upheld. She is loved and hated. As can happen to any normal person, she becomes known in certain circles for something other than what she intended. It’s a pain, but one she knows she’s lucky to have. Her social media presence is trolled by animal rights protesters and zealous novelists alike. In the end, she’s offered few choices: Embrace celebrity or obscurity. Chase research dollars or abide by evidence-based principles… What’s a tender-hearted scientist to do?

There is room in any given story for both technological advancement and, oh, the humanity! We can navigate the inelegant intersection of rat telepathy and animal rights. Why don’t we? We could place blame with ignorant writers, lazy readers, or publishers who aim for the lowest common denominator, but the real answer is beautifully more complex. It encompasses everything from public funding for STEM education through social stigma for being unironically enthusiastic science nerds. It defies gender binaries and thumbs its nose at sterotypes. There is no overly simple answer.

So, let’s look beyond the obvious extrapolations from this most recent piece of sensational science news. Let there be nuance.