Criminals are born, not made. The basic definition of the word criminal is someone who commits offensive behavior within society (Harrower, 2001). The crime can range from petty theft to murder. Criminals are born, not made is the discussion of this essay, which will explore theories that attempt to explain criminal behavior. Psychologists have developed various theories and reasons as to why individuals commit crimes. These theories represent part of the classic psychological debate, nature versus nurture. Individuals are predisposed to become criminals or are created by their environment. There are various theories within the biological explanation as to why individuals commit criminal behavior, including: genetic theory, hereditary theory, psychosis, and brain injury theory. Examples of each will be shown in the next paragraphs. The first theory to explore is the hereditary one, which originates from Cesare Lombroso (1876), father of criminology, (Feldman, 1993) whose studies were conducted by morphology. Lombroso tried to show a relationship between criminal behavior and physical characteristics. Lombrosco suggested that an individual was predisposed to becoming a criminal, as a result of internal or innate characteristics, rather than environmental factors. Lombroso observed both criminals and noncriminals based on their physical abnormalities, such as measurements and physical exams. He concluded that most prisoners displayed the same physical abnormalities, which supported his claim that they belonged to the same criminal type. Abnormal features may have included; large jaws, high cheekbones, large ears and extra toes and fingers. Lombroso stated that these physical "stigmata" indicates... in the center of the paper... Psychology in Practice: Crime, London, HodderJOSEPH, J (2001), Is crime in the genes: A Critical review of Twins and adoption studies of crime and antisocial behavior.LEO, J and CASTRONOVO,V (1985), Behavior; Are criminals born and not made? [online], available at: http://www.time.com/time/magazine/article/0,9171,960148,00.html#ixzz1ayjFrn6N[accessed 16 October 2011]MCGUIRE,J (2004) Understanding Psychology and Crime; Perspectives on Theory and Action, New York.PENNINGTON, D (2002), Introducing Psychology: Approaches, Topics and Methods, London, Hodder ArnoldTANNENBAUN, B, (2007),Professionals link criminal behavior to genetics [online], Available at 'address: http://thedp.com/index.php/article/2007/11/profs_link_criminal_behavior_to_genetics [accessed 16 October 2011].http://www.docstoc.com/docs/41182390/Explanations-of-Criminal- behaviour