Who's the Smarter Sibling?

For decades, scientists have been squabbling over birth order like siblings fighting over a toy. Some of them say being a first-, middle-, or lastborn has significant effects on intelligence. Others say that's nonsense. Whichever rings true, such studies have long fueled the fires of sibling rivalries around the world. A look at some famous siblings—and who stands out—over time and place.

Cain and Abel
According to the Old Testament, Cain and Abel were the first and second sons of Adam and Eve, born after the Fall of Man. It’s not quite clear who the smarter sibling was, but Cain eventually became so jealous of Abel that he killed him—committing the first act of murder.

Set and Osiris
Legend has it that the ancient Egyptian God Set hated his older brother Osiris so much that he built a coffin to match Osiris’ s measurements, held a banquet and proclaimed, "Whoever fits it wins!" Osiris, of course, fit just right, and when he got in, Set sealed the lid and threw him into the Nile.

Bill and Roger Clinton
Former U.S. president Bill Clinton is a Rhodes Scholar and regarded as one of the greatest public speakers of all time. After an unsuccessful bid at a music career, younger half brother Roger has served time for cocaine charges and been arrested for drunk driving (he avoided jail time by pleading guilty to the charge of reckless driving) between guest starring on a number of television shows.

Liam and Noel Gallagher
Though famous for their public squabbles, both the combative brothers were essential to the success of British rock band Oasis in the 1990s. But elder brother Noel, who plays guitar, allegedly wrote most of the band’s songs—despite the fact that Liam was Oasis's lead singer. Though Liam has contributed songs to more recent albums, his habit of starting fights and wreaking havoc has led fans to believe that Noel is the one who has kept the band on track. The British music mag New Musical Express has even called Noel “the wisest man in rock.”

Jimi and Leon Hendrix
Jailed for stealing a fur coat, troubled younger brother Leon was released to attend Jimi’s funeral in 1970. But his troubles didn’t end there. After Jimi’s Seattle estate was passed down to his illiterate father, Al, his adopted daughter allegedly persuaded Al to cut Leon out of the Hendrix fortune. Leon sued, but was denied. He later claimed that a purple flame shot out of the sky and Jimi appeared to him in a vision saying, “Come on, baby brother. It’s time. You’re ready,” after which Leon took up the guitar and started booking shows.

Christopher and Peter Hitchens
Elder brother Christopher, the British-born author, journalist and literary critic is much more prolific and controversial than his socially conservative brother. In 2005, he was named one of the "Top 100 Public Intellectuals" by Foreign Policy magazine and Britain's Prospect. Brother Peter spent most of his career as a reporter for the conservative British tabloid the Daily Express, leaving the paper in 2001 to write for The Mail on Sunday.

Dakota and Elle Fanning
Sibling rivalry can strike at any age, a fact 13-year-old Dakota Fanning can attest to. Dakota's ankle-biter sister, Elle, 9, is already snapping at her heels, being cast in numerous films including the award-winning “Babel.” But wresting the spotlight from Dakota will be tough—she's still the youngest person ever to have been nominated for a Screen Actors Guild award. 

Jimmy and Billy Carter
Former U.S. president Jimmy Carter worked his way from peanut farmer to the White House, and collected a Nobel Peace Prize. The younger Billy was known for drinking beer, urinating on an airport runway and registering as a foreign agent of the Libyan government.

Prince and Tyka Nelson
In promotional interviews for her 1988 solo album, Prince’s younger sister was accompanied by a large blue dinosaur called Jazz, which she kept on a leash and hugged. Fifteen years later, in an interview with The National Enquirer, she admitted to having been a crack addict who sold her body to buy food for her two sons, Sir and President.

Asha Bhosle and Lata Mangeshkar
Younger Asha has sung in nearly 1,000 Bollywood movies and has toured the world, but she is widely considered second best to her elder sister Lata. Lata, who was recently awarded the Bharat Ratna, India’s highest civilian honor, held a grudge against Asha after being forced into the role of sole supporter of their family when Asha eloped. The story of their rivalry has made it into a Bollywood film.

Ann Landers and Dear Abby
Esther Pauline Friedman (Ann Landers) and her just-minutes-younger twin sister, Pauline Esther Friedman (Dear Abby), were the famous newspaper advice columnists who allegedly didn’t speak to each other for 10 years after Abby insulted Ann in an interview.

Lech and Jaroslaw Kaczynski
The identical twins are president and prime minister of Poland, respectively, and are virtually indistinguishable, aside from Lech's tiny birthmark. The two former lawyers dominate Polish politics, founding the ruling party. Lech has a doctorate from Gdansk University and first became a senator in 2001. He was elected to the presidency in 2006 and soon appointed his unmarried brother as PM.

Elle and Mimi MacPherson
While most celebrity watchers are familiar with Australian supermodel and businesswoman Elle "The Body" MacPherson, many have seen much more of her environmentalist and younger sister Mimi, thanks to an explicit Internet video. Mimi, a former Discovery Channel presenter, ran a successful whale-watching business in Queensland's Hervey Bay, but received her third drunk-driving conviction in March of this year.

The Jacksons
It seems all the Jacksons have suffered their share of problems. Eldest sister Rebbie has been outshone by Michael and Janet, though given the controversy that's followed other members of the clan, that may have been the best she could hope for. Little sister La Toya has enjoyed moderate success as a solo artist, but has also posed with a snake for Playboy, written a salacious autobiography, made claims of child abuse against both her father and Michael and endorsed a Psychic Friends hotline.

Paris and Nicky Hilton
Paris has carved out a career as a model, singer and reality television star while the younger Nicky is mostly known for her star-studded sister. Perhaps that's for the best.

George W. and Jeb Bush
According to some accounts, middle-brother Jeb was expected to be the big success of the Bush clan. He was the more serious brother, married first and started a business first. But when the two ran for governor of Texas and Florida at the same time in 1994, Jeb lost.