Criminality Studies - Practical and Ethical issues

Ethical issues: 
- Offenders may lie about their past
- May underplay crimes for an early release
- May feel distressed or remorseful about their actions 
- Their memories may be unreliable 
== Biological ==
Practical 	Ethical
Only a handful will have a XYY chromosome abnormality, there will not be enough participants. 1in 1000. Too hard to find participants. 	It would be not ethical to say that having a specific chromosome pattern caused criminality if the link is not 100 % true. Self fulfilling prophecy may be caused, people with a ‘criminal’ gene may turn to criminality.
Chromosome abnormalities are very difficult to detect. Very few obvious signs that a person has it. 	If a criminal is told that their behaviour was due to a chromosome abnormality this may lead them to believe that they are not responsible for their actions, they can blame their genes.
There are many different types of crimes and criminals. Crimes are very different. A criminal gene as a general concept is unlikely to be found. 	Studies that have been conducted always maintaining the participants’ anonymity.
Family, twin and adoption studies often rely upon convictions and arrests. Many criminals are successful so will not be caught for their crimes and therefore will not be included in these studies.	If psychologists found a genetic link to criminal behaviour, this could be used to control individuals with a chromosome abnormality before they even commit a criminal offence; abuse of power.
== Social ==
Practical 	Ethical
Cannot carry out experiments that make someone criminal, so any social research just examined a link between criminality and social factors.	Parents may be blamed for their children’s behaviour. Should not be used to hold parents responsible for their children’s actions if this is not a certainty.
Memory is not very reliable after a few years. Asking criminals themselves might be unreliable, may blame other factors to get out of jail. 	Investigating the self fulfilling prophecy as an explanation may create existing labels and therefore encourage criminal behaviour.