Twins have been written about and revered in mythology for centuries, going back to the fabled founding of Rome by Romulus and Remus, abandoned at birth and mothered by a wolf. Apollo and Artemis were twins born to Zeus, the mythic Greek king of the gods. And it was Greek mythology  that inspired the astronomer Ptolemy, who in the second century A.D. described 48 constellations of stars in the zodiac and named Gemini (Latin for “twins”) after the mythical twins Castor and Pollux.

Twins can be monozygotic (identical) or dizygotic (fraternal). Identical twins are derived from one fertilized egg that splits in two, and are always the same sex. They have similar facial features and the same DNA.

Fraternal twins are formed from two eggs, fertilized separately. They may be the same or different sexes, often look different, and share about half their DNA. The birth rate for identical twins remains constant throughout the world and appears to be unrelated to factors such as a mother’s age.

The birth rate for fraternal twins, by contrast, differs from country to country, and increases for older mothers as a result of fertility drugs and in vitro fertilization. The birth rate for twins in the United States between 1980 and 2009 rose 76 percent, and is currently at about one in 85 births.

Why do twins fascinate us so? On a visual level, the sight of two identical people is arresting, and has us scrutinizing them for distinguishing characteristics. We are used to a world of unique individuals, and our equilibrium is jarred by the mirror image of identical twins.

From an emotional standpoint, the closeness shared by most twins, begun by sharing a womb for nine months, is well known. Who wouldn’t want a sibling who is almost an extension of yourself, a constantly supportive person who reinforces your thoughts and feelings by confirming them in themselves? Intimacy, sharing, trust, and empathy, all values we admire, seem an intrinsic part of the twin experience.

From the 15 sets of twins currently enrolled as undergraduates at Harvard, Gazette photographers chose four sets to provide a window into the lives of this special segment of the student body.

 

1 Freshmen Anna (left) and Anne Raheem ’19 arrived at Harvard from Tennessee delighted to experience their undergraduate years together. The fraternal twin sisters find it reassuring to know they have each other. “If I was missing home, I would have a piece of home with me here,” Anna says. Stephanie Mitchell/Harvard Staff Photographer
2 The Raheem twins stay connected through their academic interests and extracurricular activities. Both plan to concentrate in bioengineering with a possible secondary concentration in government, international relations, or a language program. They are both active in the South Asian Association, Ghungroo, Harvard Political Review, Harvard College Engineering Society, Harvard Women in Computer Science, Harvard Islamic Society, and Harvard Caribbean Club. Stephanie Mitchell/Harvard Staff Photographer
3 “When you’re together and you’re twins, a lot of people perceive you to be the same person,” says Anne Raheem. “Our parents encouraged us to be our own unique individuals.” Stephanie Mitchell/Harvard Staff Photographer
4 Since their arrival on campus, the Raheem sisters’ relationship has evolved. “We were put into this whole new world. It is an entirely new way of living … everything about this place is completely revolutionary,” says Anne. Stephanie Mitchell/Harvard Staff Photographer
5 As Anne and Anna Raheem look beyond their years at Harvard, “Who knows where we’ll be in three years?” Anna says. “No matter where we end up, we’ll have each other’s back.” Stephanie Mitchell/Harvard Staff Photographer
6 Identical twins Alex (left) and Eli Lee ’17 watch April snow flurries from a Leverett House gateway. Kris Snibbe/Harvard Staff Photographer
7 “Joining the [WHRB] Record Hospital eased my greatest concern about Harvard: that people here wouldn’t be weird enough,” says Eli Lee. “If you’d told me three years ago that in college I would be able to study Central Asian languages during the day and debate hardcore scene politics at night, I wouldn’t have believed you.” Kris Snibbe/Harvard Staff Photographer
8 Eli (left) and Alex Lee ’17 admire a giant mixed-media work by classmate My Ngoc To ’16 in the Carpenter Center. Alex has studied drawing and film as part of his undergraduate concentration. Kris Snibbe/Harvard Staff Photographer
9 “My brother and I have always been very different, but the more insular environment and limited opportunities of our hometown prevented us from exploring our different pastimes and interests,” says Alex Lee. “At Harvard, I’ve been able to involve myself in the performing arts community while maintaining a strong friendship with Eli. Even though our interests are very different, we do our best to support each other — Eli comes to my improv shows, and I go to events at the Advocate and tune into his radio show!” Kris Snibbe/Harvard Staff Photographer
10 “I didn’t set out to go to the same school as my brother, but I don’t regret it,” says Alex Lee. “We don’t have to see each other all the time — and we don’t, really — but it’s good to know there’s someone here who will always have my back. No one understands you like your twin, after all.” Kris Snibbe/Harvard Staff Photographer
11 Identical twins Alannah (left) and Grace O’Brien are in their first year at Harvard. Alannah writes, “I get mixed up with my sister almost too many times to count. For example, one day in Annenberg Hall, a guy I didn’t know came up and said hi to me. It soon became clear that he thought I was Grace. When I told him I was Grace’s twin, he thought I was pranking him, and it took some convincing.” Rose Lincoln/Harvard Staff Photographer
12 The O’Brien twins hail from nearby Brighton, Mass., and will live in separate undergraduate Houses next year. Grace says, “I think being a twin has made my experience at Harvard both easier and harder. We are very close, so it’s nice to have someone around who will always be there for me. However, throughout high school and elementary school, we were treated almost like the same person, which was frustrating. So we decided to lead completely different lives at Harvard.” Rose Lincoln/Harvard Staff Photographer
13 For concentrations, both O’Brien girls are undecided, but Grace is leaning toward government. “We participate in different extracurricular activities, hang out with different people, and we don’t plan on choosing the same concentration,” Grace says. “This allows us to lead separate lives, while staying close.” Rose Lincoln/Harvard Staff Photographer
14 Grace O’Brien says, “Obviously my sister and I are not telepathic, but we know each other so well that generally it’s easy to tell what the other is thinking.” Rose Lincoln/Harvard Staff Photographer
15 Alannah O’Brien will live at Lowell House next year, while Grace chose Quincy House. Rose Lincoln/Harvard Staff Photographer
16 Harvard sophomores Nicholas (left) and Beau Bayh ’18 are twins from Indiana. Both have an interest in politics and social service, as well as athletics. They stand at the entrance to the Harvard Kennedy School in front of a sign that reflects their desire to serve: “Ask what you can do.” Jon Chase/Harvard Staff Photographer
17 Beau (left) and Nicholas Bayh ’18 stand in the Taubman Center at Harvard Kennedy School. Their interest in public service stems from a family legacy: Their grandfather Birch Bayh and father, Evan Bayh, have both served as their state’s governor and U.S. senator. Jon Chase/Harvard Staff Photographer
18 Beau (left) and Nicholas Bayh ’18 juggle balls with sticks from their respective sports. Beau is on the lacrosse team, while Nick plays for a competitive club tennis team at Harvard. Jon Chase/Harvard Staff Photographer
19 Harvard sophomores Beau (left) and Nicholas Bayh toss a ball on the turf at Harvard Stadium. Jon Chase/Harvard Staff Photographer
20 Twin sophomores Nicholas (left) and Beau Bayh ’18 stand in Harvard Stadium, holding aloft the flag of Indiana, where both their father and grandfather were well-known politicians. Jon Chase/Harvard Staff Photographer