When most people hear about serial killers, they automatically think that there is a horrible person who likes to kill people. There's actually a lot more to them that people don't understand. Research on serial killers can date back to the early 1900's. there has also been a lot of sistical information learned about them that would give you percentages of how many serial killers went at certain times, even locations of which race has the most serials killer. Some of the information I learned is why serial killers like to kill, the differences between male and female serial killers, and sistic information about their race, IQ, and why America has had more serial killers by far than any other country. Over the years, many theories have been formulated as to why seril killers kill and crimes that had to do with childhood. A typical boy's childhood would be going to school and playing with friends. This is pretty much the opposite for a serial killer. Many studies have been conducted on the childhoods of serial killers and how they were treated by family members. ***http://listverse.com/2013/01/02/10-most-common-traits-of-potential-serial-killers/ has compiled a list of the 10 most common traits of serial killers as children. Of the 10, the top 3 are Physical Injury, Acting Out Animal Fantasies, Preference for Autoerotic Activities. Not many people would think that head banging would cause a person to act or think a certain way, but approximately 70% of all serial killers had some type of head trauma during childhood or adolescence. One part of the brain that is sometimes affected by serious head injuries is the limbic brian. The limbic system is the part of the brain that divides victims between male and female serial killers. Females largely tend to kill victims they know and are close to (Geringer, 2). This could range from family members to someone they provide care for, such as a nurse or carer. Most males do not have a relationship with their victims (Geringer, 2). They will choose a stranger and stalk him until they are ready to carry out their crime (Geringer, 2). That said, you'd think it would be harder to spot males since the victims are random, but the scale of their crimes easily gives them away.*** SIMILARITY Although male and female serial killers look very different, there are three main similarities. The first is their ability to present themselves as normal-looking citizens. Most of society believes that all serial killers look like Hannibal Lecter (Geringer, 2).