1. Biochemical Factors  Biochemical factors include: Food allergies – substances that cause severe allergic reactions. Food allergies – substances that cause severe allergic reactions. Diet – high in sugar and carbohydrates, vitamin deficiency and excessive food additives. Diet – high in sugar and carbohydrates, vitamin deficiency and excessive food additives. Hypoglycemia – low blood sugar levels. Hypoglycemia – low blood sugar levels. Hormones – abnormal levels – steroids and PMS. Hormones – abnormal levels – steroids and PMS. ©2012 McGraw-Hill Ryerson Ltd.LO5

2. Neurophysiological Factors  Neurophysiological studies have included a wide range of investigations Brain tumors Brain tumors Brain waves (EEG abnormalities) Brain waves (EEG abnormalities) Cerebral structure Cerebral structure (FAS) Fetal alcohol syndrome/(FASD) fetal alcohol spectrum disorders (FAS) Fetal alcohol syndrome/(FASD) fetal alcohol spectrum disorders (MBD) Minimal brain dysfunction (MBD) Minimal brain dysfunction (AD/HD) Attention deficit/hyperactivity disorder (9x more common in delinquent children) (AD/HD) Attention deficit/hyperactivity disorder (9x more common in delinquent children) ©2012 McGraw-Hill Ryerson Ltd.LO5

3. An Integrated Theory  Wilson & Hernstein  Nature develops from the interplay of psychological, biological and social factors.  It is the interaction of genes with the environment that in some individuals forms the kind of personality likely to commit crimes.  “the offender offends not just because of immediate needs and circumstances, but also because of enduring personal characteristics, some of whose traces can be found in his behaviour from early childhood on.” ©2012 McGraw-Hill Ryerson Ltd.LO5