biological explanation of crime: XYY Flashcards
what does the XYY theory focus on?
the genetic makeup of a person and chromosomal abnormalities due to random mutations
what is a chromosome?
thread like structure made up of DNA found in a cell’s nucleus
how many pairs of chromosomes do humans have?
23
during normal development, what does the 23rd pair consist of?
sex chromosomes
what are the female sex chromosomes?
XX
what are the male sex chromosomes?
XY
where did the first XYY research occur and what was found?
what does XYY syndrome involve?
an extra Y chromosome resulting in 47 instead of 46
how often does XYY syndrome involve?
1/1000
what are the characteristics of XYY syndrome?
- tall
- large teeth/head
- acne
- curved pinky fingers
- lack of empathy
how can XYY lead to criminal behaviour?
behavioural problems including being very active or impulsive and emotional difficulties such as anger and lack of empathy
what is the link between crime and autism/ADHD in XYY males?
the males have an inability to learn via conditioning and cannot respond appropriately to social cues which could lead to antisocial behaviour
what is a strength of XYY syndrome as an explanation of crime (PEE)?
- stockholm
a strength of XYY syndrome as an explanation of crime is supporting evidence from Stockholm. they found that there was a significant increase in the number of convictions in a group of males with XYY compared to general incidences of crime in general population. therefore, this supports the positive correlation between criminal behaviour and having XYY.
what is a strength of XYY syndrome as an explanation of crime (PEE)?
- Jacobs et al
a strength of XYY syndrome as an explanation of crime is supporting evidence from Jacobs et al. they found that 15/1000 males in prison have XYY in comparison to the 1/1000 in the general population. therefore, this supports the concept that males with XYY are overly aggressive and lack empathy which is why there is a greater percentage in prison.
what is a weakness of XYY syndrome as an explanation of crime (PEE)?
- criticism
a weakness of XYY syndrome as an explanation of crime is that it lacks internal validity. this is because the research is correlational so only a link can be found between an extra Y chromosome and crime making it hard to establish a cause & effect. therefore, a third variable could be the reason for the crimes, such as socioeconomic background or genetics e.g raised testosterone levels.