@Rangers asked a question yesterday, https://www.girlsaskguys.com/social-relationships/q2925140-what-s-the-point-of-being-a-criminal and I was interested in it. When I was in college I majored in both psychology and criminal justice for a while. Eventually I dropped criminal justice, but I still find the subject interesting.
Looking through some of the responses, and think over some of my old beliefs I realized that we often believe false things about the cause of crime. Thus I decided to do a myTake about it and hopefully after reading this you'll have learned something!
Firstly, I want to dispel one common myth. When asked what leads to an increase in crime many people understandably will point out that they think unemployment rates effect criminality. They hypothesis is that people who become unemployed turn to crime, perhaps out of anger or necessity. The problem with this is that the research is inconclusive on the subject. Some research will show a statistically significant correlation between the rise of unemployment and crime rates, but others will show that in fact there's no correlation. http://journals.sagepub.com/doi/abs/10.1177/02601079X9000300305?journalCode=jiea
If unemployment isn't a reliable indicator of criminality then what could be?
Many people are wary of positing biological or genetic predispositions to criminality, but in this case it appears very likely that biology is the strongest factor in determining one's propensity for crime. Does this mean that researchers have found the "Crime Gene" have we conducted genetic research and pointed to something in particular that determines criminality? No, well on second thought perhaps, but I will not go into the neurology here. Maybe another day. Instead in order to demonstrate the likelihood that biology is the greatest factor involved in criminality we will look at three types of studies; adoption, twin, and adopted twin studies. If you don't typically look at scientific research, especially psychological, you may not know what these types of studies are, thus I'll give a brief description of each.
Adoption studies are one helpful way to determine the environmental and genetic factors of a particular trait. What will typically happen is that a researcher will talk to an adopted child and it's biological parents. What the child has different from their biological parents can be considered to be a result of environment, and what they share can be considered to be genetically based.
Twin studies are largely used to determine whether or not there is a genetic link to a particular trait. In these studies researchers typically look at the probability any two random people will share a trait in a population, and then compare that rate to siblings and mono/dyzigotic twins. If the trend is far more significantly correlated with monozygotic twins than the general populace it can be considered to have some basis in biology.
Adopted Twin Studies: Many of you may have realized a problem with the last type of study. You may have noted that most monozygotic twins will share the same environment, more so than most members of the general population. That is the purpose for these adopted twin studies. These studies look at twins separated at, or shortly after birth and looks to determine if the trait looked for is correlated. Unfortunately, there are no well done systematic studies of this kind in relation to the biological basis of crime.
We are thus left with the adoption and twin studies. These studies still strongly point to a genetic factor involved in criminality. I will give two examples below.
A Swedish national adoption study of criminality: K. S. Kendler, S. Larsson Lönn, N. A. Morris, J. Sundquist, N. Långström, and K. Sundquist is an adoption study which consisted of 18,000 adopted away children in which it is demonstrated that regardless of adopted parent influence children who's biological parents were criminals were at a greater risk of offending than their counterparts.
Criminality and Delinquency in Twins: Aaron J. Rosanoff, Leva M. Handy, Isabel Avis Rosanof, shows a strong statistical correlation between dizygotic twins. In this study out of 33 pairs of monozygotic twins 22 pairs were both criminals. This stands in stark contrast with the number of dizygotic twins, of the 23 twins only 3 pairs were both criminals. The difference in the rate between the two is likely counted by the genetic factors.
The second most consistently correlated factor with criminality is peer group. Parental influence (other than biological) appears to have little effect, or at most it's inconsistent within the literature. Judith Rich Harris pointed out the problems with this belief of parental influence on offspring in exhaustive book, The Nurture Assumption. She quite humorously states "Poor old Mum and Dad: publicly accused by their son, the poet, and never given a chance to reply to his charges. They shall have one now, if I may take the liberty of speaking for them.
How sharper than a serpent's tooth
To hear your child make such a fuss.
It isn't fair—it's not the truth—
He's fucked up, yes, but not by us."
Contagion and repeat offending among urban juvenile delinquents Jeremy Mennis, Philip Harris is one of the best articles on the subject, but unfortunately I can no longer access it to get y'all the statistics so I would instead recommend, Gang Membership, Delinquent Peers, and Delinquent
Behavior by Sara R. Battin-Pearson, Terence P. Thornberry, J. David Hawkins, and Marvin D. Krohn. This study shows that self professed gang members were about 10 times more likely to have gotten a violent or nonviolent offense within the past year when compared with their peers who reported that 1 or less of their best friends were engaged in such behavior.
Anyway, this was more difficult than I thought as I am no longer in college and thus do not have access to a lot of the studies I wanted to point out. Hopefully it was still coherent. Thoughts appreciated.