When the people around us reinforce the words at a sermon or a Holy Text (usually these people will be family and friends , they have the most impact) then we can still say that religion has changed or influenced a change in the way we behave and what we say. No one factor acts independently from another but they all have an impact (whether negative or positive ), that much we've learnt from the social sciences.

Dag, does the poll matter or not? Either way you just dug yourself a hole. You're making yourself look inconsistent.

A simple question like, "did you go to church last month" would be quite reliable. Asking "Do you go to church often" would not be.

Why does this even require explanation?

*sigh* I would have thought this was basic understanding of polls and statistics. Polls are reliable for verifiable concrete questions. Questions that hove social bias towards one answer makes polls without extra verifiable data unreliable. Within the same poll, some questions can be reliable and some can not be. For example, normally self identification polls are not reliable. However, we would not say that the person who identifies themselves as "Jim" is really not Jim but is a "Bob." Nor would we doubt the age/race/sex of the self identification. When polls start asking more broad questions like "Are you a good person" then the data becomes much less reliable.

A simple question like, "did you go to church last month" would be quite reliable. Asking "Do you go to church often" would not be.

Why does this even require explanation?

According to the New Testament book of Acts, early converts to Christianity in Ephesus who had previously practiced sorcery burned their scrolls: "A number who had practised sorcery brought their scrolls together and burned them publicly. When they calculated the value of the scrolls, the total came to fifty thousand drachmas." (Acts 19:19, NIV) The term sorcery refers to magical practices.

In 367, Athanasius, bishop of Alexandria called in all non-conforming texts from the Christian monasteries of Egypt.

After the conquest of Toledo, Spain (1085) by the king of Castile, it was being disputed on whether Iberian Christians should follow the foreign Roman rite or the traditional Mozarabic rite. After other ordeals, it was submitted to the trial by fire: One book for each rite was thrown into a fire. The Toledan book was little damaged after the Roman one was consumed. Henry Jenner comments in the Catholic Encyclopedia: "No one who has seen a Mozarabic manuscript with its extraordinarily solid vellum, will adopt any hypothesis of Divine Interposition here."

The provincial synod held at Soissons (in France) in 1121 condemned the teachings of the famous theologian Peter Abelard as heresy; he was forced to burn his own book before being shut up inside the convent of St. Medard at Soissons.

During the 13th century, the Catholic Church waged a brutal campaign against the Cathars of Languedoc (smaller numbers also lived elsewhere in Europe), culminating in the Albigensian Crusade. Nearly every Cathar text that could be found was destroyed, in an effort to completely extirpate their heretical beliefs; only a few are known to have survived.

The burnings of Hebrew books were initiated by Pope Gregory IX. He persuaded French King Louis IX to burn some 12,000 copies of the Talmud in Paris in 1243. He was followed by subsequent Popes. The most ferocious haters of Judaism and Jewish books among them were Innocent IV (1243-1254), Clement IV (1256-1268), John XXII (1316-1334), Paul IV (1555-1559), Pius V (1566-1572) and Clement VIII (1592-1605). They almost succeeded in stamping out Jewish books entirely. Yet Jews continued to pen their holy books without cease, and once the printing press was invented, the Church found it impossible to destroy entire printed editions of the Talmud and other sacred books. Johann Gutenberg, the German who invented the printing press around 1450, certainly helped stamp out the effectiveness of further book burnings. The tolerant (for its time) policies of Venice made it a center for the printing of Jewish books (as of books in general).

In 1410 John Wycliffe's books were burnt by the illiterate Prague archbishop Zbyněk Zajic z Házmburka in the court of his palace in Lesser Town of Prague to hinder the spread of Jan Hus' teaching

In the 1480s Tomas Torquemada promoted the burning of non-Catholic literature, especially Jewish Talmuds and, after the final defeat of the Moors at Granada in 1492, Arabic books also.

In 1497 the Bonfire of the Vanities, preached by Girolamo Savonarola, consumed pornography, lewd pictures, pagan books, gaming tables, cosmetics, copies of Boccaccio's Decameron, and all the works of Ovid which could be found in Florence.

In 1499 or 1500, in Andalucia, Spain, over a million Arabic and Hebrew books from one of the richest collections in history were burned on the orders of Cisneros, Archbishop of Granada (See: Henry Kamen, The Spanish Inquisition, London: White Lion, 1965, p. 98.) Many of the poetic works were allegedly destroyed on account of their symbolized homoeroticism. (See: Erskine Lane, tr. "In Praise of Boys: Moorish Poems from Al-Andalus," 1975).

In 1525 & 1526 William Tyndale's English translation of the New Testament were burned wherever the authorities could find them.

In 1553, Servetius was burned as an heretic at the order of the city council of Geneva, without being defended by John Calvin, on a remark in his translation of Ptolemy's Geography. "Around his waist were tied a large bundle of manuscript and a thick octavo printed book", his Christianismi Restitutio, three copies of which have survived.

1562 Fray Diego de Landa, acting bishop of the Yucatan, threw into the fires the sacred books of the Maya

Martin Luther's German translation of the Bible was burned in Germany in 1624 by order of the Pope.

In 1948, at Binghamton, New York children - overseen by priests, teachers, and parents - publicly burned around 2000 comic books.

In the 1990s congregants of the Full Gospel Assembly in Grande Cache, Alberta, Canada burned books with ideas in them that they did not agree with, or that they deemed to contain ideas contrary to the teachings of God.

There have been several incidents of Harry Potter books being burned, including those directed by churches at Alamogordo, New Mexico, Charleston, South Carolina, and Cedar Rapids, Iowa.

Why would 'religious belief has changed my behaviour' be unreliable? It is asking about discrete events, deliberate conscious actions.

As an addendum to my previous post, this is a compendium of book burning incidents primarily motivated by Christianity.
(Source: Wikipedia on book burning.)

Incidents of book burning motivated by non-Christian reasons have generally been associated with politics (During the French revolution, Russian communism, the Nazi party, and Pinochet in Chile) or other religions (Such as Salman Rushdie's books.)

And I haven't included events in which books were merely banned, rather than burnt, such as the Index Librorum Prohibitorum.

In other words, Europe has a strong history of book burning as a means to bring about political and societal change, weather its affective or ineffective.

To get any value out of that question you need a second question that reads "I believe that religious belief affects people's behaviour."

You mean like the question "Has your obesity affected your behaviour" requires the second question "I believe that obesity affects people's behaviour" to have any value?

I mean, its not like the answer to the second is implicit in the first.

Actually, yes.

The answer to the second question can help you a lot in learning more about the answer to the first question. Especially when comparing which people answered which way.

Note, however, how almost every incident is motivated by the Church. Even when supported by the state, the motives are usually religious. When such motivation isn't religious, it was almost always in backlash against religion. There was a single incident of non-religious book burning in Europe until as late as the twentieth century.

Yes, and lets not forget that new churches and religious movements were created when States didn't like the restrictions of the existing ones. I do not think that you can separate church from state activity in Europe before the 1700s.

Why do you suppose that would change the result, however?

Even though most book burning is done in purely theological grounds? And even though those same Protestant churches have burned books themselves?

Also, do you claim religion has little or no effect on people's behavior?

It would not change the result, it would change how you interpret the result.

If 80% answer yes to the first question and 90% answer yes to the second question, then I would not rely on the first question to be of any use, and would need outside data.

If 80% answered yes to the first, but only 20% answered yes to the second, then it would be more helpful in determining to what degree obesity affects people's behavior. Of course you need follow up questions to find out which behaviors it affects. Does it affect curtosy, or does it only affect frequency of going to the gym and doing physical activities.

And curtosy is not a word.

Institutions affect people's behavior, and social circles affect people's behavior. Any place you go where people gather and interact will affect your behavior.