Genetics & Antisocial Behavior
- 1. AN INTROTO GENETICS Genetics and Antisocial Behavior
- 2. I.B. Learning Outcomes ■ I can explain how much our genes impact our behavior. ■ Possible Essay Prompt:To what extent do genetics impact human behavior?
- 3. ToWhat Extent True NotTrue Consider the merits or otherwise of an argument or concept. Opinions and conclusions should be presented clearly and supported with appropriate evidence and sound argument.
- 4. Behavioral Genetics ■ The study of how the both genetics and the environment contribute to individual variations in human behavior. ■ Genes do not cause behavior, they create a predisposition towards it.
- 5. Definition of a Gene ■ Genes are the working subunits of DNA. Each gene contains a particular set of instructions, usually coding for a particular protein or for a particular function.
- 6. Inheritance ■ Each offspring inherits traits from their parents. ■ 46 Chromosomes – 23 from Mom, 23 from Dad ■ ~20,000-25,000 genes
- 7. Key ideas about Genetics ■ Genes that we inherit from our parents give rise to physiological functions which contribute to physical and behavioral characteristics. ■ One Gene does not lead to a behavior, it can be a building block towards that behavior.
- 8. Twins
- 9. Twin Studies ■ Identical Genetic Make Up ■ Different Environments ■ Look for similarities and differences between monozygotic twins ■ Nature & Nurture ■ Is It All In the Genes?
- 10. Raine & Baker (2007) ■ Aim:To investigate the impact of genetics on antisocial behavior (bullying, cruelty, aggression, etc.). ■ Method: – Participants: 1,210 twins in California. – Gave a behavioral survey to the twins, their parents, and their teachers of the twins to measure for antisocial behavior. – Used a statistical measure to compare the rankings of fraternal and identical twins’ correlations.
- 11. Raine & Baker (2007) ■ Findings: Regardless of the reports they used (twins, parents, or teachers) the results always showed a 50% heritability rating. ■ Conclusion: About half of the antisocial behavior of the participants could be traced back to genetics. ■ Explanation?CriticalThinking?
- 12. Grove et al. (1990) ■ Aim:To measure the genetic impacts on antisocial behavior. ■ Method: – Participants: 32 sets of separated identical twins. – Conducted tests, questionnaires, and surveys to measure antisocial behavior in each individual.
- 13. Grove et al (1990) ■ Findings: – Adults: 21% of antisocial behavior was attributed to genetics. – Children: 41% of antisocial behavior was attributed to genetics. ■ Conclusion: While genetics play an important role in shaping antisocial behavior, the environment plays a larger role. ■ Explanation? CriticalThinking?
- 14. Serotonin ■ A neurotransmitter with the function of stabilizing mood and maintaining “balance” in the brain. ■ Low levels of serotonin have been linked to depression, anxiety, and other personality disorders.
- 15. MAO-A Gene ■ Codes for Serotonin in the Brain. – Low Activity: Low amounts of Serotonin – High Activity: High Amounts of Serotonin ■ Impacts the development of the Amygdala. ■ Also known as the “Warrior Gene” because those who have a variation of it do not feel the calming effects of serotonin.
- 16. Ferguson et al. (2011) ■ Aim:To investigate the relationships between the MAOA gene, exposure to violence, & violent behavior. ■ Method: – Participants: 398 Males in New Zealand who had been demonstrated with Antisocial Behavior. – Performed a genetic test when they were 28-30 years old. – Surveyed the men for exposure to violence/trauma as children & their own violent behaviors.
- 17. Ferguson et al. (2011) cont. ■ Findings: – Those who had Low-Activity MAOA Gene were significantly more likely to commit violent crimes than men with the High- ActivityGene if they had experienced trauma. ■ Conclusion – Low-Activity MAOA Gene &Trauma increase the rates of violent behavior. ■ Explanation? CriticalThinking?
- 18. Antisocial Personality Disorder ■ A condition that leads to a general lack of empathy for others, a disregard for the rights of others, a lack of guilt, and often a disregard for laws or social morals. ■ Psychopaths: Lack of connections with others but are able to present charming personalities. Often times very successful and can appear normal. Crimes are often highly calculated. ■ Sociopath: Easily agitated and nervous. Can often make limited connections with others. Holding down jobs or gaining an education is difficult. Crimes are often disorganized and spontaneous.
- 19. Questions to Consider. ■ Should violent psychopaths be punished more or less severely if their behavior can be blamed on brain differences or genes? ■ To what extent is nature or nurture responsible for violent crimes? ■ To what extent are crimes determined or the result of free will? ■ To what extent do genetics impact violent behavior?