Modern researchers would argue that no one is born to be a criminal. However, there are various biological factors that can contribute to criminal behaviors. There are several theories regarding the biological nature of criminality and these include genetics, brain abnormalities, and neurochemical imbalances.
Biological factors that contribute to criminal behavior are the most significant considerations to study in order to learn about the criminal psychology. There are three main biological factors that have a contribution to the criminal behavior. Criminal behaviors had been always questioned on rather it is caused by nature or nurture on the field of behavioral sciences since the early 19th century.
The first factor that leads to criminal behavior is genetics. They are the outcome of individual genes received from their parents at the time when they are born.
In order to determine the extent to which genetics may play a role in the criminal activity, psychologists have carried out twin studies. German physiologists, Johannes Lange, have conducted an investigation with a group of thirteen pairs of adult male identical twins. He found out that if one twin had a record of imprisonment, the other pair similarly had been imprisoned in seventy-seven percent of the cases; whereas in a comparable group of seventeen pairs of fraternal twins, when one twin had been imprisoned, the other had a prison record in only twelve percent of the cases. Johannes have proposed a conclusion that criminal behavior among identical twins were greater than fraternal twins.
Another factor, which also counts as a biological factor is the brain. According to their structure of the brain, psychologists can determine rather they have a possibility to cause a crime or act in a criminal behavior.
The research on brain has focused primarily on the correlation between emotions and decision making. Emotions are usually controlled by the limbic system in our brain while decision making takes place in the frontal lobe.
The last factor of a biological factor is about neurotransmitters and hormones. There are lots of research conducted in this area to prove to criminal behaviors. Neurotransmitter is a chemical substance that is released at the end of a nerve fiber by the arrival of a nerve impulse and, by diffusing across the synapse or junction, causes the transfer of the impulse to another nerve fiber, a muscle fiber, or some other structure (Kendra 2018). These chemical messengers can influence wide range of both psychological and physical functions.
Low levels of the neurotransmitter serotonin have been linked to antisocial and impulsive behavior. Interestingly, men-who are responsible for the vast majority of crimes committed-generally have lower levels of serotonin. In addition, Jaines Dabbs has demonstrated that violent criminals have higher testosterone levels than nun-aggressive criminals.