Data on pro- and anti-social behaviour are drawn from the Gallup World Poll. The Gallup World Poll is conducted in over 140 countries around the world based on a common questionnaire, translated into the predominant languages of each country. With few exceptions, all samples are probability based and nationally representative of the resident population aged 15 years and over in the entire country, including rural areas. While this ensures a high degree of comparability across countries, results may be affected by sampling and non-sampling error. Sample sizes vary between around 1 000 and 4 000, depending on the country. Pro-social behaviour averages country responses to three questions about whether the respondent has volunteered time, donated money to a charity and helped a stranger in the last month. Anti-social behaviour averages responses to questions on whether the respondent has had money or property stolen in the last year and been assaulted. The Gini coefficient is a measure of income inequality. Values range between 0 – perfect equality – and 1 – all income goes to one person.