It is widely believed that there is an inverse relationship between socio-economic status (SES) and criminality. That is, people from low-SES backgrounds are over-represented amongst the population of offenders. For example, stereotypical views of “the criminal” frequently include the motion that they are working classes. Whilst some research supports the idea that low SES is associated with criminality, the relationship between offending and SES is weaker than many people assume. One issue that arose from earlier studies of the relationship between SES and criminality was that the relationship appeared much stronger for official measures of offending than for self-report measures. This finding may reflect bias in the way that people from different social backgrounds are processed by the criminal justice system, as some studies have shown that low SES can militate against a defendant at trial. Rutter and Giller (1983) found a small correlation between SES and crime but it is open to question what the origin of this is. Sociological theorists favor explanations based around the relative lack of opportunities open to people from low-SES backgrounds, whilst more psychologically oriented theorists tend to indicate the learning of delinquent values from family and peers as possible explanations of criminal behavior.