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最も信仰があつい国はどこで、最も無神論的な国はどこだろうか？ その答えを見つけるために、調査会社などで構成されるWIN-Gallup Internationalは、57の国々からデータを収集して「Religion and Atheism Index」（信仰および無信仰指標）をまとめた。
この信仰指標は、「祈りをささげるような場所に行くかどうかにかかわらず、あなたは自分を信仰のあつい人間、信仰の薄い人間、あるいは明らかな無神論者のどれであると表現しますか」という質問に対して、自分を「信仰のあつい人間」と答えた人が人口に占める割合を表している。
興味深い点をいくつか挙げてみよう。
1. 貧しい人々の方が、裕福な人々よりも信仰があつい。収入が最も少ないグループでは、収入が最も多いグループと比べて、信仰のあつい人が17％多い。
2. 世界的に見ると、信仰があついと述べる人々の数は、2005年から2011年にかけて9％減少している。一方で、自分を無神論者だとする人の数は3％増加している。
3. 2005年から2012年にかけて、信仰のあつい人が総人口に占める割合が20％以上減少している国が4つある。フランスとスイスで21％の減少、アイルランドとベトナムで23％だ。
[以下の画像ギャラリーでは、「信仰のあつい国」と「最も無神論的な国」のランキングを紹介している。日本は、「無神論的な国ランキング」の第2位となっている。]
Most To Least Religious Countries
ガーナ（96％が「信仰があつい」）(01 of21)
Ghanaian cardinal Peter Kodwo Appiah Turkson attends a mass at the St Peter\'s basilica on March 12, 2013 at the Vatican. Cardinals moved into the Vatican today as the suspense mounted ahead of a secret papal election with no clear frontrunner to steer the Catholic world through troubled waters after Benedict XVI\'s historic resignation.The 115 cardinal electors who pick the next leader of 1.2 billion Catholics in a conclave in the Sistine Chapel will live inside the Vatican walls completely cut off from the outside world until they have made their choice. (credit:GABRIEL BOUYS/AFP/Getty Images)
ナイジェリア（93％が「信仰があつい」）(02 of21)
Machete and axe wielding neighbourhood vigilantes hop into a pick-up on July 19, 2013 for an operation to hunt down Boko Haram Islamists in Maiduguri, where Boko Haram has carried out most of its deadly attacks in a four-year insurgency that has left some 3,600 people dead since 2009, according to Human Rights Watch. Young men and women have in recent weeks formed vigilante groups, hunting down Boko Haram Islamists who have sneaked back into the city following a military offensive on their camps on the Nigerian border with Niger, Chad and Cameroon with remarkable success. AFP PHOTO / Aminu ABUBAKAR (Photo credit should read AMINU ABUBAKAR/AFP/Getty Images) (credit:Getty Images)
アルメニア（92％が「信仰があつい」）(03 of21)
This photo taken on January 5, 2013 shows a man lighting a candle during a Christmas Eve service at the Khor Virab church outside Yerevan. Millions of Armenians will celebrate Christmas on January 6. (credit:KAREN MINASYAN/AFP/Getty Images)
フィジー（92％が「信仰があつい」）(04 of21)
Pilgrims from Fiji attend the morning Mass of Pope Benedict XVI at Randwick Racecourse in Sydney on July 20, 2008. Far fewer people than the predicted crowd of 500,000 turned out for a final World Youth Day mass led by Pope Benedict XVI on Sunday, leaving one venue almost empty of worshippers, AFP photographers said. (credit:KRYSTLE WRIGHT/AFP/Getty Images)
マケドニア（90％が「信仰があつい」）(05 of21)
The president of Macedonia\'parliament Trajko Veljanoski kisses the hand of Pope Francis during a private audience on May 24, 2013 at the Vatican. (credit:GABRIEL BOUYS/AFP/Getty Images)
ルーマニア（89％が「信仰があつい」）(06 of21)
Visitors light up candles inside a room \'The space for Recollection and Prayer\' to commemorate victims of the communist repression in Romania, in Sighetu Marmatiei on July 13, 2013. Former dissidents and political prisoners gathered in Romania on July 14, 2013 at a museum commemorating those who suffered abuses under communism, set up 20 years ago at the site of a prison where scores died. (credit: DANIEL MIHAILESCU/AFP/Getty Images)
イラク（88％が「信仰があつい」）(07 of21)
Iraqi Muslim men wait before breaking their fast, in a meal known as Iftar, inside a tent dedicated to cooking and eating during Ramadan, which is the first of its kind in the capital Baghdad. A group of Iraqi businessmen are providing free Iftar meals for poor people during Islam\'s holy fasting month of Ramadan where observers must abstain from food, drink and sex from dawn to dusk. AFP PHOTO/AHMAD AL-RUBAYE (Photo credit should read AHMAD AL-RUBAYE/AFP/Getty Images) (credit:Getty Images)
ケニア（88％が「信仰があつい」）同率7位(08 of21)
Njemps tribemen dance in front of a statue of Buddha at the Gallmann nature conservancy near Kinamba, Laikipia, Northern Kenya on March 4, 2012. High Priest Shinso Ito and a group of Shinnyo-en priests arrived in Kenya to perform a Buddhist fire and water ceremony for the first time ever in Africa.The ceremony was attended by over 300 spiritual leaders and was streamed live on the internet to millions of viewers and devotees globally. The ceremony involved Kenyan tribal elders and members of the Njemps, Pokot Samburu, Kikuyu and Turkana communites. AFP PHOTO/Carl de Souza (Photo credit should read CARL DE SOUZA/AFP/Getty Images) (credit:Getty Images)
ペルー（86％が「信仰があつい」）(09 of21)
A faithful holds an image of the \'The Lord of Miracles\', worshipped by the majority of the Catholic Peruvians, during his main procession on October 18, 2012 in Lima. (credit:GERALDO CASO/AFP/Getty Images)
ブラジル（85％が「信仰があつい」）(10 of21)
Catholics touch an icon of the Virgin Mary and Jesus Christ as it is taken along with the World Youth Day (WYD) Cross that in 1984 Pope John Paul II entrusted the youth of the world, across Rocinha shantytown in Rio de Janeiro on July 18, 2013. The Pope is due in Rio for the July 22-28 Catholic WYD, an event expected to attract two million people from around the globe. (credit:Photo credit should read YASUYOSHI CHIBA/AFP/Getty Images)
アイルランド（10％が「無神論」）(11 of21)
description 1 Celtic cross, Irish National Heritage Park This fine reproduction is in the Celtic monastery section of the park. ... (credit:WikiMedia:)
オーストラリア（10％が「無神論」）(12 of21)
A Falun Gong Practitioner poses on the 14th anniversary of the beginning of the persecution of Falun Gong in China on July 21, 2013 in Sydney, Australia. In July of 1999, the communist Chinese government outlawed the spiritual practise of Falun Gong, declaring it illegal and forbidding citizens to practise. Followers believe thousands of practitioners have been killed, imprisoned or put in labour camps in China since 1999. (credit:(Photo by Brendon Thorne/Getty Images))
アイスランド（10％が「無神論」）(13 of21)
Pope Benedict XVI (R) poses with Iceland president Olafur Ragnar Grinsson during a private audience at the Vatican on March 4, 2011. (credit:ALBERTO PIZZOLI/AFP/Getty Images)
オーストリア（10％が「無神論」）(14 of21)
The Russian Orthodox cathedral of St. Nicholas is seen on a clear day in Vienna on April 1, 2013. (credit:ALEXANDER KLEIN/AFP/Getty Images)
オランダ（14％が「無神論」）(15 of21)
Dozens of people queue in front of the Nieuwe Kerk in Amsterdam on May 1, 2013. A day after the crowning of king Willem-Alexander the church has opened it\'s doors for those who want to see the church in the same setting as during the ceremony on April 30. (credit:JERRY LAMPEN/AFP/Getty Images)
ドイツ（15％が「無神論」）(16 of21)
Eight new priests prepare for their ordination at the Freisinger Dom cathedral on June 29, 2013 in Freising, Germany. Freising Cathedral, also called Saint Mary and Corbinian Cathedral, is a romanesque basilica in Freising, Bavaria. The Freising Cathedral is also known for being the place where Pope Benedict XVI was ordained a priest. Bavaria, Germany\'s southern-most state, is heavily Catholic. (credit: (Photo by Alexander Hassenstein/Getty Images))
韓国（15％が「無神論」）(17 of21)
Nuns walk on a popular shopping street in Seoul on July 6, 2013. Freedom of religion is constitutionally guaranteed in South Korea, which is predominantly Buddhist and Christian. (credit:Ed Jones/AFP/Getty Images)
フランス（29％が「無神論」）(18 of21)
A picture taken on July 12, 2013 shows a nun walking by the Sacre-Coeur basilica in the Montmartre neighborhood of Paris. (credit:PATRICK KOVARIK/AFP/Getty Images)
チェコ共和国（30％が「無神論」）(19 of21)
Tourists enjoy a sunny day on March 25, 2010 at the traditional Eastern market in the Old Town Square in Prague. (credit:MICHAL CIZEK/AFP/Getty Images)
日本（31％が「無神論」）(20 of21)
写真は、2013年6月にスペインの大聖堂で行われたコンサートに出席する皇太子殿下。 (credit:Photo by Concha Paz-Pool/Getty Images)
中華人民共和国（47％が「無神論」）(21 of21)
写真は、イスラム教を信仰するウイグル族の男性。新疆ウイグル自治区トルファンにて撮影。 (credit:MARK RALSTON/AFP/Getty Images)
[Yasmine Hafiz(English) 日本語版：平井眞弓／ガリレオ]
Top 10 Most and Least Religious States
#1: Mississippi (59 percent)(01 of22)
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#2 Utah (57 percent)(02 of22)
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#3 Alabama (56 percent)(03 of22)
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#4 Louisiana (54 percent)(04 of22)
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#5 Arkansas (54 percent)(05 of22)
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#6 South Carolina (54 percent)(06 of22)
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#7 Tennessee (52 percent)(07 of22)
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#8 North Carolina (50 percent)(08 of22)
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#9 Georgia (48 percent)(09 of22)
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#10 Oklahoma (48 percent)(10 of22)
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#51 Vermont (23 percent)(11 of22)
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#50 New Hampshire (23 percent)(12 of22)
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#49 Maine (25 percent)(13 of22)
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#48 Massachusetts (28 percent)(14 of22)
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#47 Alaska (28 percent)(15 of22)
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#46 Oregon (30 percent)(16 of22)
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#45 Nevada (30 percent)(17 of22)
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#44 Washington (30 percent)(18 of22)
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#43 Connecticut (31 percent)(19 of22)
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#42 District of Columbia (32 percent)(20 of22)
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#42 New York (32 percent)(21 of22)
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#42 Rhode Island (32 percent)(22 of22)
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