In the Spring of 2015, the Ad Council put together a video called “Love has no Labels.” In the video, a giant X-ray screen is set up in the downtown area of a major city. Behind the screen various couples are dancing and kissing—though the gathering crowd sees nothing more than skeletons. Then comes the big reveal, when the crowds discover that the affectionate couple was a pair of women. The video underscores this point, saying: “Love has no gender.” The video went viral. The point seemed inescapably clear. As Slate’s J. Bryan Lowder puts it, “if we can get past our surface prejudices, love looks the same.”
But is gender merely a matter of “surface prejudices?” Sure, the contrast may not be as obvious, but a trained eye can spot the differences between a male and female skeleton—primarily (though not exclusively) in the bones of the hips and pelvis. So the ad said more than it intended. The ad’s message was that our differences are a matter of “surface prejudices.” But the reality is that our differences go all the way to the bone.
SEX AND GENDER
First, let’s clarify our terms here. In his work on gender dysphoria (a subject we’ll return to later on), Mark Yarhouse articulates a threefold distinction between sex and gender:
- Biological Sex: “As male or female (typically with reference to chromosomes, gonads, sex hormones, and internal reproductive anatomy and external genitalia).”
- Gender : “The psychological, social, and cultural aspects of being male or female.”
- Gender identity: “How you experience yourself (or think of yourself) as male or female, including how masculine or feminine a person feels.”
- Gender role: “Adoption of cultural expectations for maleness or femaleness.”
So, for clarity, here’s what that might look like for a traditional understanding of sex and gender:
No one disputes the existence of obvious biological differences between men and women. In their book Same Difference, Rosalind Barnett and Caryl Rivers suggest that gender goes deeper than mere biology. “Of course there are differences between the sexes,” they write. “But more important is the size of difference between men and women compared to those among women and men.” Any call to traditional gender norms “belies the energy we see around us, as our society embraces new freedoms and discovers new tolerance, rejecting old stereotypes. …More freedom…allows us to be more varied, complex, and unique than does a world shackled by the iron bars of a gender-difference culture.”
MALE AND FEMALE
But the differences between men and women are hardly superficial. It’s probably already obvious to point out that men have a higher basal metabolism and cardio capacity—that’s why men tend to have higher muscle mass and tougher bones and ligaments.  But what might be less obvious is the way that men and women each have a radically different brain structure and thought process. So much so that in recent years, some researchers have suggested that “brain sex [i.e., the sex of the brain] is paramount in determining human gender identity.” There’s an astounding body of data on this, but it might be more helpful to look at some of the more interesting ways it plays out in everyday life—many of which are detailed in the early chapters of Leonard Sax’s influential work, Why Gender Matters.
- If you’re a father with a teenage daughter, have you ever had this conversation: “Stop yelling at me!” “I’m not yelling at you.” We don’t even have to specify who’s the father and daughter in that exchange. Why? Well, women Women tend to have a more acute sense of touch, hearing, smell, and taste.  So the father and daughter are experiencing the same sound in two different ways.” What seems normal to a forty-three-year-old sounds like yelling to a seventeen-year-old.
- Ask a woman and man to give directions and you’ll get radically different sets of instructions. Sax tells us that according to the best research, “women typically navigate using landmarks that can be seen or heard or smelled. Men are more likely to use absolute direction such as north and south or absolute distances such as miles or city blocks.” Why? Because “young women use the cerebral cortex while young men use the hippocampus, a nucleus deep inside the brain that is not activated in women’s brains during navigational tasks.”
- In summer of this past year, Target announced that they would be introducing “gender-neutral” labels for some of their children’s sections—most notably the toy aisle. This has been good news for parents of children who’d just as soon play tea party as construction worker. But while gender-specific toys aren’t a rigid category, there are key differences in the preferences of young boys and girls that can’t be explained away by culture. According to Sax, studies in both humans and monkeys have shown that girls tend to be concerned with things such as color and texture—and answering the question “What is it?” Boys, on the other hand, tend to be more focused on action, speed—answering the question “Where is it now?” “So we shouldn’t be surprised,” Sax says, “that young females…prefer dolls over trucks, while young males…prefer trucks over dolls.” In other studies, these preferences appear as early as nine-months old—well before culture has had its chance to influence these choices.
While it may be true that differences in gender may be culturally expressed, we can’t say that gender differences are culturally constructed. If that were true, then every culture’s gender roles would look wildly different. But, as Gregg Johnson points out in his article on gender differences, “of two hundred fifty cultures studied, males dominate in almost all….The fact that these universals transcend divergent animal groups and cultures suggests that there must be more than a cultural basis for these sex differences.”
GENDER AND THE SOUL
Why gender? Why such differences? Perhaps our biological differences hint at something far deeper. One spiritual writer puts it this way: “Our sexuality penetrates to the deepest metaphysical ground of our personality.” That is, our identities as male and female go far deeper than we can ever hope to measure through biology or psychology. “As a result,” he says, “the physical differences between the man and the woman are a parable of psychical and spiritual differences of a more ultimate nature.” 
Gender points beyond itself to a greater and more beautiful design. Yet how can we affirm this design if gender roles are assumed to be human inventions? How do we celebrate gender roles without bowing to gender stereotypes? How do we ennoble our young men and women to see their differences as signs of strength, not weakness?
 J. Bryan Lowder, “Beyond the Visible Spectrum, Love Looks the Same,” http://www.slate.com/blogs/outward/2015/03/04/watch_this_brilliant_ad_council_x_ray_skeleton_video_about_love_video.html
 Mark A. Yarhouse, Understanding Gender Dysphoria: Navigating Transgender Issues in a Changing Culture, p. 17.
 Ibid., 18.
 Rosalind Barnett and Caryl Rivers, Same Difference: How Gender Myths are Hurting our Relationships, Our Children, and Our Jobs, p. 13.
 Ibid., 254.
 A. Glucksman, Sexual Dimorphism in Human and Mammalian Biology and Pathology (Academic Press, 1981), pp. 66-75.
 Gaya Aranoff and Jennifer Bell, “Endocrinology and Growth in Children and Adolescents,” in Marianne Legato, ed. Principles of Gender-Specific Medicine, p. 12.
 Durden-Smith and Desimone, Sex and the Brain, pp. 71-73.
 Leonard Sax, Why Gender Matters, p. 18.
 Sax, 25-6.
 Ibid., 26.
 A. Powlowski, “Target removing ‘gender-based’ signage after complaints from parents,” Today.com, August 10, 2015, http://www.today.com/parents/target-removing-gender-based-signage-after-complaints-t37711
 Sax, 22.
 Anne Campbell et al., “Infants’ Visual Preference for Sex-Congruent Babies, Children, Toys and Activities: A Longitudinal Study,” British Journal of Developmental Psychology, 18:479-98, 2000.
 Gregg Johnson, “The Biological Basis for Gender-Specific Behavior” in Recovering Biblical Manhood and Womanhood, Wayne Grudem and John Piper, eds., p.282.
 Emil Brunner, Das Gebot und die Ordungen, quoted in Paul Jewett, Man as Male and Female, p. 173.