Tuesday, August 8, 2017

The Science of Sex Differences: It's Complicated (and Biased).

UPDATE: An updated version of this  was published at This View of Life. Head over there to read it!



There's a lot of discussion about the problematic Google manifesto, and one of the issues that's brought up is the science of sex differences. Part of the problem is that it's easy to cherry-pick evidence to support your own biases. Based on research on young chimpanzees, I could claim that humans have an evolutionary basis for females to be tool-oriented and males to be more socially-oriented. But it's actually quite harder to truly understand human sex differences because we still don't have the data to fully understand them. 

If you only know a little bit about human biology, it might sound simple. XX or XY? Ovaries or testicles? Estrogen or testosterone? But in reality, there's a wider range of developmental possibilities.  Development of sex-typical traits isn't just determined by the sex chromosomes, but is guided by multiple pathways that start in the womb, and continue through adulthood. For example, individuals with androgen insensitivy syndrome (AIS) may be XY, and produce androgens such as testosterone, but may develop female-appearing or intersex genitalia due to lack of functioning androgen receptors. Furthermore, the actions of any given hormone is interdependent on many other hormones, proteins that bind to them, and enzymes. For example, testosterone plays a role in male sex drive, but only because its converted to estradiol in the brain. Hormones can also have somewhat paradoxical effects. For example, administering oxytocin, a hormone associated with social bonding, in experimental settings can make people more trusting, but it can also make them more xenophobic. But most importantly, hormones are calibrated to developmental environment and daily experiences, which means which we can't attribute anything we measure in adult humans to "just" biology or genetics.


So, biology is complicated. BUT, measuring biology is equally as complicated, and very susceptible to biases. The impact of these biases in shaping scientific  research was explained by Stephen Jay Gould in the Mismeasure of Man, and others (such as Marlene ZukHolly Dunsworth, and Ambika Kamath) have added to that. But we are still far from overcoming those biases. Biomedical research has only recently begun to require including female rodent models. Most of our understand of mammal biology and neuroscience comes from rodents, but its still largely biased toward understanding male rats. And most of understanding of human psychology and neuroscience is biased toward Western, Industrialized, Educated, Rich, Democratic (WEIRD) populations. That means a lot of the science of sex differences is based on the norms of a limited set of cultures. Furthermore, the research process often requires weeding out 'outliers.' Imagine that you are researcher studying sex differences in personality in a population of university students. Are you going to include students who are intersex or trans? Probably not. Are you going include students who are gay or bi? Probably not. To get the nice, neat data you are looking for, your selection criteria requires omitting a lot of the variation that could obscure your results. And even the variation you do see at that stage is going to be shaped by the common cultural enviroment your participants were raised in.

There's an extensive body of literature on sex differences in children, but many of these are attributed to socialization. It's impossible to separate the impact of biological sex from the influence of gender socialization that begins from birth. There's a reason baby clothes are so strongly gendered--it gives people cues that impact how people respond to "girl" or "boy" babies. This makes it very hard for us to separate out out the impact of biological sex versus the impact of cultural socialization in shaping sex-typical behavior.

But one area in which we have growing evidence is in the impact of perceptions of gender (and ethnicity) in evaluating students and potential job candidates. Research indicates that simply switching a name can influence how someone is perceived. For example, candidates for a lab manager position with a female name are rated as less competent, and offered lower salaries, despite equal resumes. And manipulating the gender or ethnictiy of a name can influence the likelihood of getting a response from prospective supervisors. There's also research showing that class indicators help men receive positions, but decrease opportunities for women.

Add to that hostile or unsafe environments and harassment, and we can see evidence of cultural barriers to women's participation and advancement in some areas of science and technology. So why are these discounted? Quite simply, it all comes back to those biases. We all have cognitive biases, and they are shaped by our cultural environment. In the study examining candidates for lab managers, female scientists were just as biased as male scientists in evaluating female-named candidates. We can take steps in critically examining our biases and take steps to account for them in our research and hiring practices. But nonetheless, part of "overcoming" those biases is realizing that we can never completely overcome biases, and instead recognize how they shape the science that we do and the we way we evaluate the competency of the people around us.

To examine your own biases, check out Harvard's Project Implicit. For further reading on the role of hormones in development, I recommend Randy Nelson's An Introduction to Behavioral Endocrinology. For more background in biases in studying human traits, I recommend Stephen Jay Gould's The Mismeasure of Man.





Monday, July 17, 2017

Smart Sakis: A Spoonful of Termite Mound helps the Bitter Seeds Go Down

Captive Sakis at the Como Zoo

One of my academic siblings, Dara Adams, just published some interesting new research from Saki monkeys in Peru!

New Scientist has a nice summary, as well as accompany video, see feel free to check that out!



Saki monkeys are a Neotropical primate found in Amazonia. They are seed predators, which means that rather than ingesting seeds and passing them whole (like spider monkeys), their teeth and digestive system destroy the seeds they eat. This is a good way to get maximum nutrition from those seeds, but the seeds contain high levels of secondary compounds like tannins. Tannins are the bitter, astringent compounds that give coffee, tea, and wine their unique flavors, but high levels of tannins (much higher than we consume), can be toxic.  Other Amazonian seed predators, like parrots, eat soil with clay and high cation exchange capacity, both of which neutralize the toxic effects. Seeds eaten by parrots in the same region have tannin levels toxic to most verterbrates. If the Sakis are eating the same seeds, how do they cope with those levels of toxins?

Sakis eat termite mounds, which contains soil, clay, and nutrients. Adams and colleagues tested between two hypotheses: 1) Sakis eat the termite mounds because they provide nutritious minerals (like vitamins), or 2) to help counteract the potentially toxic effects of secondary compounds (like a detox supplement). If the soil they ate from termite mounds contained more micronutrients, that would support the vitamin hypothesis. If the soils contained that have more clay and and cation exchange properties, that would support the detox hypothesis.

They observed how long the monkeys ate termite mounds, which age/sex classes at the termite mounds, if there were termites present. They also collected samples from termite mounds that the Saki fed at, and compared to control soil samples and unvisited termite mounds.

About 2/3 of the termite mounds contained termites, and Sakis did eat termites at the active mounds. However, they fed from both active and inactive termite mounds, all age/sex classes fed on the mounds. Termite mounds did have higher levels of some minerals than topsoil, and those levels were similar in the both the Saki-eaten mounds and univisited mounds. The eaten- and uneaten-termite mounds did not differ in in clay content, but the termite mounds that were eaten had twice the cation exchange capacity. Adams and colleagues conclude that the Sakis are eating the termite mounds primarly because it helps counteract the effect of the tannins, supporting the detox hypothesis.

So basically, Sakis are wisely self-medicating with termite mounds to counteract the effects of their potentially toxic diet!

An important caveat: Adams and colleagues do not use terms like the "vitamin" or "detox" hypothesis--I use these terms only to simply the function of termite-mound eating. Also, humans are not seed predators, so we do not have the same need for detoxing. Most talk of "toxins" in human diets is pseudoscience, and unless you're eating some strange things that are not suitable for human consumption, you should have no need for detoxing!

Tuesday, July 11, 2017

Who Tells your Story?


Recently, there's been a lot of twitter discussion on the negative experiences of women in academia, and follow-up discussions on the experiences of POC and WOC in science.

These discussions dovetail with my current research, as well as recent research published by members of my lab.

Women in science experience biasdiscrimination, and harassment, and these experiences are intensified for women of color.  Many of us know this personally or anecdotally. But we're at the stage where more of those experiences are being shared openly, and some personal and anecdotal information (which is so easily dismissed or denied by others who haven't experienced it) is being codified in peer-reviewed data.

But I have mixed emotions as I read others responses, and grapple with my own analysis of qualitative data on women of color's experiences. It's INCREDIBLY important that people contribute to these discussions. But in response to the concern that people might not want to share openly, there was an anonymous survey posted, so that those responses could be shared on Twitter. And something about that made me uncomfortable.

Often, we can only share those stories anonymously, because of the discomfort of bringing attention to our own experiences, or the fear of negative reprisals. BUT, I worry that when we report those eexperiences anonymously to others, we give away the power to tell our own stories. Storytelling has power, and those stories have power regardless of who's telling them. But I'm reluctant to tell my own stories in an anonymous way, because I don't want to give away agency over my own story.

This puts pressure on me to consider the way I report the qualitative data I've gathered from participants. Other people have entrusted me with their stories. How do I report on the emerging themes from those accounts while giving them full agency over their own experiences? This is a question I'm going to have to keep thinking about as I move forward in analysis and writing.

 But for my own stories I'm not ready to share many of my experiences openly on Twitter, nor do I want them to give them away to be told anonymously. I want to maintain agency over my own story, so that I can tell it on my own terms.

I highly recommend reading Ambika Kamath's perspective, I Have Forgotten. Also, in case you were under the impression that only underrepresented minorities experience discrimination in science, read RajLab's Anti-Asian Bias in Science.

Monday, June 26, 2017

Is that "cute" animal picture a depiction of abuse?



Behind the chimp-proof glass is former entertainment chimp Kendall (now in a social group at the North Carolina Zoo)

Cute animal pictures are the best part of social media.  But as a primatologist, there's also "cute" pictures that make me cringe. Every birthday there's at least one picture posted to my wall of an entertainment chimp fear-grimacing. And frequently, I have to be the killjoy explaining to someone why the picture or video they're sharing is problematic.

This happens too often. Today, the picture drawing my ire was an entertainment chimp illustrating a news story on the Science magazine website (though they quickly changed it when we raised concerns on Twitter- thanks @NewsfromScience for being responsive!). 

No one wants to be the killjoy ruining the fun. But if you understand the context behind the picture, it stops being a cute picture, and becomes a disturbing depiction of abuse and suffering. 

Several studies demonstrate that pictures of primates increase the belief that they are desirable as pets, or aren't endangered. And viral videos can increase demand for the illegal pet trade. 

So how do you tell the difference? Sometimes it's hard, but other times it's very simple. These guidelines are focused on primates, but apply to many wild animals as well.

1) Does the picture depict a primate dressed in human clothes, wearing makeup, playing with phones, or otherwise depicting unnatural behavior?

DON'T SHARE. These are tell-tale signs that the animal is in the entertainment industry, or a pet. In both these situations, animals are taken from their mothers at an early age, deprived of typical socialization, and often abused and mistreated. Occasionally there are exceptions (photoshop or monkeys grabbing phones from tourists), but these pictures can promote the idea that they are desirable pets.

2) Is the primate in an unnatural-looking setting?

PROCEED WITH CAUTION. Sometimes these are pictures of pets, or animals housed in a roadside zoo or pseudo-sanctuary. However, in other cases it might be animals in an unnatural-looking but enriching enclosure at an accredited zoo. For example, the bonobos at the Columbus Zoo have a very unnatural looking indoor enclosure, but they have a lot of fun climbing structures and varied enrichment.

Juvenile bonobo at the Columbus Zoo (where the enclosure is unnatural but enriching!)

3) Does the picture show an unnatural pairing (for example, a monkey and dog pair) that probably doesn't occur in the wild?

PROCEED WITH CAUTION. Some of these pictures may be unlikely friendships that occur in the wild, or in humane captive environments (such as zoos or accredited sanctuaries). However, exploitative roadside zoos and pseudo-sanctuaries put unlikely pairings together because it generates attention. See if you can figure out where it was taken before you share.

4) Does the picture depict a "wild" primate sitting on someone's shoulders?

DON'T SHARE. And more importantly, don't put yourself in this situation! These may be wild animals that are fed to encourage tourist interaction, or they may be captured animals that are abused and displayed for tourists. It's dangerous for both the animals and, and the humans, because primates can cause serious injuries and diseases can easily be transmitted between humans and primates (and Herpes B, which causes benign cold sores in macaques, is lethal to humans). 

5) Is the picture a gorilla splashing around in a giant kiddie pool at an accredited zoo?

SHARE AWAY! Provided it is a picture from an accredited zoo (context is everything), this is one of those situations in which the unnnatural setting provides a captive animal with a lot of fun enrichment!







Still have questions? That's okay, there's often a lot of gray area or lack of context. If you're not sure, but think it MIGHT be exploitative... err on the side on the side of caution and avoid the "share" button. And if you're not sure, feel free to ask a primatologist (if you tweet me @MARspidermonkey, I"ll give you my assessment)!


Tuesday, March 14, 2017

10 Reasons Spider Monkeys could be the #2017MMM Champions

Most of the winners of March Mammal Madness tend to be large-bodied, terrestrial mammals, so it might be easy to overlook a twenty-pound, arboreal frugivore. But don't let their small size, endangered status*, or predominantly vegetarian** diet fool you! They are fierce competitors!

So, here are 10 reasons why spider monkeys are awesome and have a real shot at being the #2017MMM champions.

Adult Female Margarita at Brookfield Zoo.

1. They are smarty-pants! They are highly encephalized, with very large brains for their body size

2. We've observed them using tools, and they have a number of social traditions.

3. They have self-control. On inhibition tasks, they perform comparably to chimpanzees and orangutans (and better than capuchins and macaques)!

4. They are speedy and FLY through the trees. I'm pretty sure that they only way I was able to follow spider monkeys is that they let me tag along.

5. They are ferocious killers. Seriously. Male coalitions engage in territorial raids and lethal aggression, and there are observations of infanticide as well.

6. Their prehensile tail assists in semi-brachiation, but can also be used as an extra hand. I used to know a captive spider monkey who would use her tail to check my pockets for hidden snacks. Their tail even has "fingerprints" (aka, dermatoglyphics) to help them grip!

Look at that those tail "fingerprints!"


7. Although they are highly arboreal and dependent on tropical forest, they can travel on the ground. When males engage in raids, they walk silently, single-file on the ground (just the way chimpanzees do on raids)!

8. Although there is limited evidence for this, reports from a re-introduced population in Barro Colorado Island suggest that they may swim short distances between islands!

9. They tend to be lefties, just like me! In humans, unexpected left-handeness can provide a strategic advantage in sports and competition.

10. They are so darn cute. Yes, I know that MMM is about combat, not a #cuteoff, but since animals use a variety of tactics to win these battles, surely charming the opposition is a legitimate strategy?

Infant male Judah (ca 2010). Isn't he the cutest?!

*Most Ateles species are endangered, but they range from vulnerable to critically endangered.
**Spider monkeys are predominantly frugivores, but in addition to fruit they do eat leaves, flowers, and insects. Most of the insects they consume, like fig wasps, are within the fruit they eat.


Tuesday, January 24, 2017

Resistance is Never Futile





Saturday, we made history, and it was one of the most amazing days of my life.

The train downtown

I saw the pictures on social media of women on planes, on trains, in buses, and at rest stops, all traveling to DC. When I waited with friends to take the train in Chicago, we watched our already-filled train speed past us, and boarded a second train, which quickly filled up. It was like the march was began right on the platform into Union Station. The city was alive with a stream of signs and hats, and men and women pouring through the loop to get to Grant Park.

At the Rally

During the rally, we were far enough that we couldn't see or hear anything actually going on for the rally. We stood, and chatted, and took pictures and admired signs.We watched the helicopters swirling above. I speculated about how someday, when the kids of the future learn history from virtual reality holodecks, they might be stepping into our pictures and video and virtually marching with us.

" We all move forward when we recognize how RESILIENT and STRIKING the women around us are. "--Rupi Kaur



We had no idea what was going on, and no one around us could get a connection to access social media on phones. After the "march" was supposed to happen, some people cutting through the crowd said there were tweets saying the march was cancelled. But eventually the crowd started to move, the marshalls told us to turn around, we followed the crowd, and we marched.

The giant IUD was one of my favorite "signs"


We marched, and we chanted. "This is what democracy looks like," "Our bodies, our choice/Her body, her choice," "Black lives matter," "We're here, we're queer, we're fabulous." The atmosphere felt positive, energetic, inclusive, intersectional. There were certainly a whole lot of white ladies, but there were women of different races and ethnicities, men, and range of sexualities and identities. There were babies, and older kids, and plenty of grandmothers. There were signs in Spanish and Arabic. It was an amazing and unforgettable experience.

My run buddies double as march buddies


And then when I went home and caught up with social media, I saw my friends posting from cities all over the US. I saw pictures and video of marches from different cities, different states, and different countries. We marched in every state! There was a tiny town in Idaho, where half of the town's 63 residents came out to march! We marched all around the world, on every continent! Even some penguins turned out!

From: https://twitter.com/VeraMBergen/status/822885195464458241


I hope we can hold on to that momentum and the motivation, because things are getting scary FAST. The current administration is doubling down on outright lies, cracking down on scientific research and communication, and going forward with the Dakota Access Pipeline. In just four days, there's been a terrifying move to suppress facts, suppress science, and endanger womens' rights, indigenous rights, and the environment.

We still have more work do on building a intersectional movement. But as we do that, we need to continue to keep resisting. There is so much that is frightening and overwhelming, and I'm not quite sure how to cope with it. But we need to keep up the calls, the e-mails, the protests, and reminding everyone we know that this is not normal.

Facts are verifiable. Science is real. We are entering a fascist, authoritarian rule and this is not normal. Resistance is never futile, and we have to keep at it. Let's keep on holding onto those truths.

Here are a few of the resources I've been drawing on to keep up with action items.

Action Checklist for Americans of Conscience

Action for a Better Tomorrow (IL)

It's Time to Fight

Indivisible Guide

Women's March 10 actions/100 days


I'm going to keep scrolling through the amazing footage of the marches, and singing this song when I need motivation.


Sunday, January 8, 2017

Science, Politics, and Remaining Sane in a Dystopian Wonderland

Right now, we're at a risk of entering a stage in US politics where the administration is explicitly anti-science, and anti-education. At this point, debates about whether or not scientists should engage in political activism are largely irrelevant, because science, education, and pretty much everything anthropologists do will be under attack.

The issue I struggle with is figuring out how to stay motivated, engaged, and actually make a difference. It's hard to stay sane when we're experience nationwide gaslighting. Since November 9, I've felt like we collectively fell down a rabbit hole and emerged in a ugly dystopian Wonderland where up is down and nothing makes sense anymore. As someone who values facts, evidence, and reason, it's a struggle to remind myself that I am still sane, when it seems like the world around us has decided to dispense with facts and reason.

But despite that, WE CAN'T GIVE UP. Nearly everything I care about is under threat, and we  have to fight to protect it. Here some of the ways of the Trumperdink* administration threatens the work I do:

*Many thanks to Cary Elwes for the appropriate nickname
  • Under a Trumperdink administration, environmental protections will be dismantled, climate research will defunded and banned (and climate scientists may face persecution), and destructive resource extraction will increase. This will intensify the rate of global warming and ongoing mass extinction--and that's going to determinentally effect spider monkeys and bonobos and all the other primates I love.
  • Under a Trumperdink administration, public education, both at the K-12 and universities levels, are going to be under assault. Betsey DeVos is anti-public education, and anti-teaching evolution. Teaching evolution is going to be under assault, so biology teachers, biologists, and anthropologists are going to face more obstacles to our teaching and our research.
  • Women, ethnic and religious minorities, gay, transgendered, and disabled people are already facing increased risks of harassment and violence. As a women of color, I'm increasingly scared for my own safety. Since my newest research project is looking at stress and resilience in female scientists of color, this is obviously going to have an impact on our research participants, and they research itself.
  • The biggest sources of scientific funding come from the government (NSF, NIH, NASA), and in an explicitly anti-science political climate, they are going to face even more cuts. 
  • Public universities have been facing systematic budget cuts because states refuse to adequately fund them. The combination of lack funding sources, and lack of resources to hire teaching faculty, means the job market for scientists and academics is going to get even worse. It's already been difficult and grim. Right now, my future is very uncertain. And I fear the jobs in science and academia will dry up entirely, and staying in science will require competing for the few international jobs available. 
Add that to the fact that I am terribly afraid that we are heading down a dark road may lead to erosion of  our rights, and potentially genocide or nuclear war. I am afraid, it's been hard to focus on my work, and I feel divided between my desire to stay informed and remain politically active, and my need to stay sane and preserve my emotional energy for the upcoming years.

One of my biggest fears is that I'll give in to hopelessness and apathy, and that will pave the way for much worse. My biggest fear, beyond the fear of mass deportations, internment camps, genocide, or nuclear war, is that when it comes down to standing up for other people's rights, and protecting myself, is that I will choose the cowardly option. 

So for now, I'm going to focus on preventing us from reaching that point. I'm going to join the people who are standing up, speaking out, and mobilizing to protect us. I've been calling my representatives again and again, and we saw last week that this works. I'm starting to become involved in local grassroots political activism, and need to learn more about government at the local level. The past semester, in the 21st Century Scientists working group, we've been talking a lot about how to communicate science across political and tribal identities. I'm still struggling with finds ways to put this into practice, but a common theme we've been discussing is the importance of storytelling and establishing common emotional ground. I hope I can find ways to adequately put this into practice. 

Another way that I've finding hope and establishing sanity is reading quality journalism (like Teen Vogue!), and occasionally detaching from social media to read fiction.  I've been processing the current political situation is to think about so many of my favorite books, both fiction and non-fiction, that dealt with individuals facing oppressive regimes. 

Here are few really important pieces I've read online. I suggest that if you haven't, you should book mark some of these to read, and re-read, to keep yourself sane and motivated.
I've heard so many friends say that they're losing hope, or that they are coping with the political situation by disengaging with news and social media. Please stay engaged, and stay hopeful. Here's one reason to stay hopeful: the 115th Congress is the most diverse we have ever had. We still have a long way to go, but let's do our work to support them.

The women representing us (Shared from Rep. Cheri Bustos on Twitter)