The problem is that many of the concepts are not testable because they cannot be operationalised. For example, it is hard to see how the number of pro-crime attitudes a person has, or has been exposed to, could be measured. Similarly, the theory is built on the assumption that offending behaviour will occur when pro-crime values outnumber anti-crime ones.Without being able to measure these, we cannot know at what point the urge to offend is realised and the offending career is triggered. This means the theory does not have scientific credibility.