Tag Archives: Sex

Music About Science

I have an opinion that might be unpopular around here: I don’t like music about science. My love of science and scientific knowledge cannot be impugned — my Ph.D. is all the evidence I need to make my case. I never would have made it through my 14 years of biology education if I didn’t love science. I even love boring science lecture — both hearing them and giving them. Music is also very important to me. I have been a casual musician for most of my life, and listening to music and making music are deeply fulfilling for me. There is a bunch of music out there that is about science, and it would be reasonable to guess that I would love this music. But I don’t. There is a time for music, and there is a time for a boring science lecture, but when I’m listening to music, what I want is not a boring science lecture.

Exhibit A:

Symphony of science is pretty popular. But let’s face it — this is literally just a boring science lecture that has been auto-tuned. The words of Carl Sagan, for example, are inspiring in their own right. I don’t think making them musical adds anything to them. If anything, I think his words are cheapened slightly by the gimmick.

Exhibit B:

I have a lot of love for Baba Brinkman, so I feel a little bit bad for listing him here. He is brilliant, great with words, and a good performer. I respect him a lot for using his medium to explain science. I particularly like the way he used this anti-evolution rally song as a base for this song about the science of political values and religion.

I got to see him perform once at an evolutionary psychology conference, and I really have nothing but love for him. For the times that I actually do want to listen to a boring science lecture set to music, I go straight to Baba Brinkman. But this doesn’t change the fact that his work is still essentially a boring science lecture, albeit spoken very rhythmically.

Exhibit C:

Hank Green’s “I Fucking Love Science” is cute. There are some clever lines, but it’s not what I want out of music. It is literal and a little bit lecture-ey at times. What I mean should be clear in a minute.

Please don’t misunderstand me — there is no judgement here. Musicians should write about whatever they want to write about, and people should listen to whatever they want to listen to. My feelings about the music I mention are just my own feelings. I also don’t mean to disparage any of these artists. I’ve tried writing music myself, and I can’t go around calling the kettle black.

This is not about what music I think people should or shouldn’t be writing and listening to, it’s just about what I want out of music. What do I want out of music? Some poetry. Some metaphor. The language of emotion. And would a drum solo kill you?

When I listen to music, I want to be able to identify with the emotions that are conveyed through the medium.

Take this song:

This song is reportedly about Kurt Cobain’s relationship with Tobi Vail, the drummer for Bikini Kill. You may not like this song as much as I do, but you will agree that at no point does this song, which is about a human relationship, sound like an anthropologist talking about the mating behavior of gorillas. The song is about the emotions, not the details. No boring lectures anywhere.

Kurt Cobain talks about his experience in this song without making the context perfectly clear. But it is deeply expressive and poetic, and it is exactly what I want out of a song.

Take another song about a relationship that ended:

Kris Kristofferson’s take on this topic has much more of a narrative style than Kurt Cobain’s. There is no question about what Me and Bobby McGee is about. But there is still poetry. He could have said, “Now she’s gone and I really miss her.” That would have communicated his point effectively, but there is no poetry to it. Instead, he chose to say, “and I’d trade all my tomorrows for one single yesterday.” Give me a minute to catch my breath.

I think the mistake that people make when writing music about science is talking like scientists instead of lyricists. There is a reason why we have scientists write our science, and musicians write our music. It has famously been said that, “Writing about music is like dancing about architecture.” Each of these media have their style, and limits to their application.

Here is what I would like to see: music about the experience of science, rather than the outcome of science. We have beautiful, poetic music about the experience of love, death, happiness, sex, jealousy, war, fatherhood, dissatisfaction, and basically every other human experience one could have. But very little beautiful, poetic music about science.

Consider, for a moment, Leonardo DaVinci. He was both a great scientist and a great artist. Remember that this was the guy who painted the Last Supper, the Mona Lisa, and the Vitruvian Man. If he was going to write a song about science, what would it have sounded like? “If the air passing over the top of a wing is moving faster than the air moving under the wing, it will reduce the pressure above the wing and create lift. La dee dee, la dee dah.” No, probably not.

Through my pursuit of science, I have experienced a wide range of emotions. Scientific discovery can be wonderful, beautiful, painful, emotional, and, at times, even exciting. Where is the music inspired by science that conveys these feelings?

You may disagree, or maybe I just haven’t heard the right music. What’s your favorite song about science?

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Sex vs Gender


America was settled by puritans. It may or may not be a coincidence that, hundreds of years later, we are still pretty weird about sex. Most people don’t even like saying the word “sex.” Enter “gender.” With the word “gender,” people can communicate their thoughts without the ickiness of having to say “sex” out loud. Or can they?

As a teacher, I often had to correct students who tried to tell me the gender of the cockroaches they were using in their experiments. Even biology professors, who really should have known better, would sometimes use the word “gender” when they meant “sex.” A friend of mine is having a baby soon. She and her husband recently made a big announcement about the gender of the baby. Official documents are notorious for items like, “Please indicate your gender: __male __female.” But what is the problem here? In short, sex and gender are not the same thing.

Sex is the biological component. Male mammals* have an X chromosome and a Y chromosome, have testicles, a penis, and produce sperm. Female mammals have two X chromosomes, have ovaries, a uterus, a vagina, and produce eggs. Sex is basically a categorical variable — you are either male or female. About 1% of people are “intersex.” For these people, there may be a disconnect between their arrangement of chromosomes and their anatomy — sometimes people will develop outwardly as male, but have two X chromosomes and no Y. The opposite can happen, too, with people developing outwardly as female, but having XY chromosomes. (People with XXY or YYX chromosomes are not considered intersex.) Sometimes people are born with ambiguous genitalia, or a mismatch between their external and internal genitalia. This throws a bit of a wrench into our concept of biological sex, but around 99% of people can be categorized comfortably as male or female. (For more information, go here.)

Gender is a psychological component. It deals with how you feel and how you present yourself. Unlike sex, which is mostly binary, gender is a smooth, continuous variable. Most human males are clustered towards the masculine end of the gender continuum, and most human females are clustered towards the feminine end of the gender continuum. But you can have males who are more or less masculine than other males, and females who are more or less feminine than other females. You can have females who are more masculine than some or most males, and males who are more or less feminine than most females. Most males identify as men, and most females identify as women, but this is not always the case. Some males identify as women, and some females identify as men — these people usually identify as “trans*” or “transgender.” (For more information, go here.)

So do cockroaches have gender? Not if the answer you are looking for is “male” or “female.” Male and female are choices for sex. Do cockroaches have a gender identity? Not as far as we know. Do cockroaches have any sense of self at all? Again, not as far as we know. There might be some scientific questions about cockroach gender, but most people don’t think about these things.

Likewise, official documents shouldn’t ask for your gender when what they really want to know is your sex otherwise the question would look like this: “Please indicate your gender on the following scale: masculine_ _ _ _ _ _ _ _  _ _ _ _ _ _feminine.”

My friend’s baby? Has a sex, but the gender will be up in the air until he or she develops a self-identity.

Both sex and gender are real things, but they are different. Make sure you’re using word you mean.

*In other types of animals, sex is determined in different ways.

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Sexy Symmetry

My recent post on attraction was, by a large margin, my most popular post yet. As this is an area of expertise for me, I’m happy to write more on the topic. This post will discuss in greater detail an aspect of attractiveness that I touched on briefly before: symmetry.

Leonardo da Vinci’s “Vitruvian Man” exhibits high symmetry. Image from http://blsciblogs.baruch.cuny.edu

The human body is designed to have external symmetry. There are certain parts of us that are designed to be asymmetric — e.g. the brain, most of our organs — but for the sake of this conversation, “symmetry” refers to the parts of us that are supposed to be symmetrical. Evolution built our bodies to be perfectly symmetrical on the outside, and there is good reason for this. For example, if our legs were not the same length or equally-muscled, walking around would be inefficient. Overall, our symmetry allows us to have mechanical balance in our bodies, and to interact with our surroundings with both sides of our body (handedness not withstanding).

That we end up basically symmetrical as adults is remarkable. When our bodies grow, they do so by the individual cells in our body dividing, growing, differentiating, and stacking up to form our limbs and organs. This process takes place over one and a half decades, and involves roughly 10 trillion cells in the end product (not counting the trillions that die along the way). A symmetrical body therefore has roughly the same number of cells in the same locations on each half of the body. This is like two cars with blind-folded drivers traveling perfectly parallel and at the same speed for hundreds of miles. But our bodies do not turn out with perfect symmetry. Developmental perturbations, such as injury or disease, can disrupt the intended course of growth. If one of the drivers in my example runs over a small rock, his course and speed will be altered slightly, and he will deviate from the other driver. The number and intensity of these perturbations will determine how different the direction and location of the two drivers will be at any given point.

Thus body symmetry is an indicator of what we biologists call “phenotypic quality.” This is just a fancy way of saying how well-built a body is. Having higher symmetry means that you were able to prevent your body from being disrupted by developmental perturbations. Indeed, people with higher symmetry have higher intelligence, faster reaction time, are more masculine (if male) or more feminine (if female), are healthier, have better mental health, better mental acuity later in life, have higher sperm quality (only in men, obviously), and have better athletic ability. This is not a comprehensive list. The relationship between symmetry and these traits is sometimes small, but there is a clear relationship overall. Symmetry does not cause these traits, but symmetry is related to these traits because they all result from a body that is well-built.

And this is why more symmetrical people are more attractive.

Success in natural selection is about leaving more surviving offspring than other members of your species. If your offspring are put together better than the offspring of other individuals, they will survive better and ultimately leave more surviving offspring themselves. Choosing mates with high phenotypic quality will increase the chance that the chooser’s offspring will have high phenotypic quality. Resistance to disease is an aspect of phenotypic quality that is of particular importance in a mate. Remember from my post on sexual reproduction that an interest in producing disease-resistant offspring is a primary reason why sexual reproduction evolved in the first place.

For this reason, humans are not alone in our preference for symmetrical mates. This preference has been found in many species of birds, fish, insects, spiders, and even plants. The preference for symmetrical mates probably evolved shortly after sexual reproduction did. In my previous post, I list attraction to symmetry as a species-typic trait, but it is typical of way more species than just humans. An interest in high quality mates is integral to sexual reproduction.


The female peahen prefers peacocks that have more symmetrical “eyes” in their tails. This one looks pretty good. Image from http://gallery.photo.net

Symmetry is important, but it is only one trait of many that are involved in attractiveness in humans. As I write more about attraction, I hope the ways in which these traits interact will become more clear.


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Hot or Not

With Valentine’s Day coming up, I thought I’d do a post about the science of attraction. The purpose of this post is not to summarize everything that we know about what makes people attractive to one another, but to explain how we think about it.

First, it is important to realize that attractiveness is not a single trait. Attractiveness is what we call an “emergent property” of many different traits — that is, people may possess many different traits that all add up to making them however attractive they are.

Attractiveness may be broken down broadly into two divisions: physical attractiveness and non-physical attractiveness. Physical attractiveness is the aspects of a person’s body that you find attractive (hands, feet, face, whatever else you’re into), and non-physical attractiveness are the personality, values and social traits of a person.

Another way of breaking down attractiveness is into how broad the preference is for certain traits. Traits may be typical of humans as a species, typical of individual cultures, or individual preferences.

Species-Typic Attractiveness

These are the traits that humans, as a species, tend to find attractive in one another. We can talk about this the same way we talk about any other trait in any other species. For example, the American lobster (Homarus americanus) is usually a reddish-brown color, but about one in two million is instead a brilliant blue color. The presence of the blue lobsters does not change the fact that the typical color of the species is reddish-brown. It just means that there are exceptions to the norm. In humans, the most basic rule of attraction is that men are attracted to women, and women are attracted to men. This is the species-typic trait. But a few percent of humans are either attracted to people of the same sex, to people of any sex, or to no one at all. The existence of these traits — which are far more common than blue lobsters — does not change what is typical of the species, nor are people with these traits any less human. We can tell when an aspect of attractiveness is species-typic when it is common across cultures and throughout time.

The following are examples of other traits that humans tend to find attractive as a species:

Symmetry is a trait that is attractive not only to humans but to many other species. People of both sexes are more attractive when they have more symmetrical faces and bodies. Denzel Washington, people magazine’s sexiest man of 1996, was once found to have an almost perfectly symmetrical face.

Examining the symmetry of Denzel Washington. Image from http://www.pleacher.com

Men are most attracted to women who have a low “waist to hip ratio” or a waist that is narrower than the hips. This is true of people across cultures and time. Waist to hip ratio (or WHR) is calculated by dividing the circumference of the waist by the circumference of the hips. Models and actresses commonly have a WHR of 0.65-0.75.  

Marilyn Monroe’s WHR was 0.63. Image from http://www.dailyhiit.com 

Conversely, women typically find men more attractive who have broad shoulders and relatively narrow hips.

Henry Cavill (as Superman) has an impressive shoulder-to-hips ratio. Image from http://www.healthyceleb.com


Men and women differ in the size of the lower face, and this difference is important in attractiveness. Women with a smaller lower face (relative to the size of the upper face) and men with a larger lower face (relative to the upper face) are more attractive. This is fairly hard to imagine from my description, but the following pictures of Mila Kunis and Nikolaj Coster-Waldau should make it more clear. Pay close attention to the shape of the jaw, the width of the jaw, and the distance from the chin to the nose:

Nikolaj Coster-Waldau. Image from http://www.virtual-history.com

Mila Kunis. Image from http://www.redcarpetnewstv.com

The most universally attractive non-physical trait is niceness. People of both sexes all over the world prefer romantic partners who are nice to them. This probably isn’t a surprise to anyone, but it has been confirmed by science.

Culture-specific Traits

Fashions for clothing, hair styles, facial hair, makeup, and jewelry are vastly different throughout time and space. High heels were originally a mens’ fashion that was later adopted by women. Nowadays a man wearing them is generally considered odd at best. Men used to show their wealth by wearing lots of necklaces and bracelets and rings. Men with wealth are still generally considered to be attractive, but modern, western conventions say “no” to all of the jewelry. Beards were in fashion when my father was young, then they were out for a few decades, now they’re coming back again. The perms of the 80s are mercifully gone, hopefully never to return.

This was all considered attractive in the 80s. Image from www.80sfashion.org

This was all considered attractive in the 80s. Image from http://www.80sfashion.org

Modern fashion often borrows things from fashion of the past, but completely adopting the style of past decades might be a little bit weird. Being weird typically makes one less attractive to others, unless you are in a culture that values being weird.

Some cultures find people more attractive when they are slim and some cultures like full figures.

The human population is the largest it has ever been, and the internet allows people to come together and form new cultures at a rate that has never been seen before. Adopting the conventions of a culture tends to make one more attractive to other members of the culture.

The “bagel head” trend gained limited popularity in Japan a few years ago. Image from global.fncstatic.com

There is limitless variation to what individual cultures may find attractive, but there are no cultures that go against species-typic attractiveness by more than a little bit.

Individual Differences

Individual differences can cover both things that have been studied as well as the wide spectrum of unique things that people find attractive about one another.

People tend to like other people who are like them. This is called “assortative mating.” Political, moral and religious values can be a very important part of this. Liberals tend to date and marry liberals, Muslims tend to date and marry Muslims, vegans tend to date and marry vegans. The same goes for personality traits and even physical traits. There are obviously exceptions, but there is a clear trend.

How we feel about a person’s personality and behavior can influence how physically attractive we find them, and vise versa. If you have a negative experience with a person who is otherwise physically attractive, you will find them less physically attractive or even physically repulsive. The opposite is true as well.

Opposites don’t usually attract, but there are notable cases when they do. The most interesting case is probably the region of the immune system called the “major histocompatibility complex” or MHC. Humans and other vertebrates prefer mates who have different genes than their own in this region.

And sometimes there are just oddities that are unique to the individual. A friend of mine in college really liked guys wearing brown pants. There may not be anything substantial to explain about that.

This is just a primer on how scientists think about attraction. The few traits that I list are just examples and are by no means an exhaustive list of what we know (and there is still an enormous amount that we do not know). Of the things that I discuss, there are many nuances that I could not discuss for length. Indeed, whole books have been written on the topic. For more on this topic, see this book and this book and others. I plan to write more on this in the future, as well.

The point of this is not to tell anyone what they should or shouldn’t be attracted to. Everyone is different and the many aspects of attractiveness can interact in endless ways. People are attracted to whoever they are attracted to, even if it’s nobody.

What I hoped to accomplish here is to share a framework for how to think about the topic. The news is full of reports on new findings about human attraction. I hope it will be easier to put these studies into context after reading this post.

And try out this line tonight:

“Hey baby, I’m heterozygous at my MHC loci.”

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Why do we have sex?

When posed with this question, most people will answer some combination of “to make babies” or “it feels good.” These answers are both true, but they are only part of the story — they describe what biologists call “proximate causes.” A proximate cause is one that explains the presence of a trait during the lifetime of the individual, compared to “ultimate causes” which are the reason why the trait evolved in the first place.

Take, for example, the opposable thumb. The proximate causes for this trait include the genes that code for it and the developmental processes that create the right environment for it to occur. The ultimate cause of the trait is that it allows us to manipulate objects in our environment with greater dexterity, therefore allowing us to get more food and survive better. All traits have an ultimate cause and a proximate cause, and both are integral to understanding the trait.

To make things a little bit more complicated, “to make babies” can be both a proximate and an ultimate cause. One thing that motivates people to have sex is the intention of making a baby. This motivation is a proximate cause. Making babies is also the ultimate cause of sexual reproduction. But even this is not the whole story. There are two basic methods of reproduction: sexual and asexual. Across all life, sexual reproduction is not the default position. Of the three lineages of life — bacteria, archaea and eukarya — only one (eukarya; the lineage to which we belong) typically reproduces sexually, and there are many species in this lineage that are asexual. Why do some types of organisms reproduce sexually and others asexually?

To put this question into perspective, let’s talk about the down-sides of sexual reproduction:

First, there is the problem of males. What exactly do males do? In a population of asexually-reproducing organisms, every individual is reproducing. Because males cannot have babies, a population of sexually-reproducing organisms can only reproduce half as quickly (because only half of the individuals are capable of reproducing). Males consume resources that would otherwise be available for females and young. Males provide parental care in relatively few species.

Second, there is the efficiency of passing on genes. Everyone knows that reproduction is about passing on your genes. When reproducing asexually, each offspring is a genetic clone of you, meaning that you are related to each offspring by 100%. With sexual reproduction, each offspring is only related to you by 50%, meaning that you need to have twice the number of offspring when reproducing sexually to match what you would have when reproducing asexually. For accounting purposes, each offspring only counts as a half.

Third, there is the problem of finding mates. In an asexual species, an individual may spend all of their energy on survival and reproduction. In a sexual species, individuals must expend energy on finding mates at the expense of survival and actually producing offspring.

I could make this list longer, but I hope I’ve convinced you that sexual reproduction has it’s shortcomings. So why on earth would the most complex organisms on earth reproduce this way?

The answer is genetic diversity. Sexually reproducing organisms are much less vulnerable to changes in the environment than asexual ones, especially when it comes to infectious diseases. Normally, individuals of a species differ in their susceptibility to a particular pathogen, and a large part of this variation is due to genetics. Some people don’t usually get the flu, whereas other people get it often and badly. This is because people are physiologically different, and therefore the flu virus cannot infect all people equally well. When two individuals reproduce sexually, their genes get mixed together in new ways. This creates a constantly moving target for pathogens. Asexual organisms do not need another individual to mate with, but all of their offspring are genetic clones of the parent. When there is lower genetic diversity, a pathogen can evolve to be better at infecting the host species to devastating effect. For example, the “regular” bananas that we buy in the store are a single strain called “cavendish” bananas. Not only are they a single strain, but every tree that produces them are genetic clones of each other. There is essentially zero genetic diversity among them, and as a result, a fungal disease is currently decimating the world’s crops.

Infectious disease is one of the biggest problems for life on earth — even many organisms that are themselves diseases can become infected by diseases. The costs of sexual reproduction may be high, but not as high as the costs of reproducing asexually when there are infectious diseases around.