Most serial killers begin their criminal careers in their 20s, often starting with non-homicidal crimes like arson or animal torture, but some first murders can occur in adolescence, with many showing early signs of violence or sexual deviance, often stemming from traumatic childhoods and abuse. While the typical range is young adulthood, juvenile serial homicide is a recognized precursor, indicating the roots of such behavior often begin much earlier than the first official murder.
The FBI, however, states, "Serial murderers often seem normal; have families and/or a steady job." Studies have suggested that serial killers generally have an average or low-average IQ, although they are often described, and perceived, as possessing IQs in the above-average range.
3,013 murderers in the United States in 2023 were individuals between the ages of 20 and 24. In the same year, there were seven murderer offenders aged between one and four years.
Many serial killers have IQs in the “bright normal” range. Organized serial killers who kill methodically, like John Wayne Gacy or Ted Bundy, have an average I.Q. of 113, while disorganized serial killers have an average I.Q. of 93. Ed Kemper had an I.Q. of 136 (140 is often used as the genius mark in I.Q. tests).
Since the 1970s and 1980s, a high activity period for serial murderers, the numbers have dropped significantly. Numbers peaked in the 1970s when there were nearly 300 known active serial killers in the U.S. In the 1980s, there were more than 250 active killers who accounted for between 120 and 180 deaths per year.
In addition, 82 percent of American serial killers were white, 15 percent were black, and 2.5 percent were Hispanic. Eighty- seven percent operated alone, while 10 percent committed their crimes in pairs or groups. Some committed their crimes in specific geographic areas, while others traveled widely.
A 72 IQ is considered Borderline Intellectual Functioning (BIF), falling just above the threshold for intellectual disability (usually around 70), placing it in the lower end of the spectrum (70-79) and indicating slower learning and potential needs for support in daily living, though it's not low enough for an official intellectual disability diagnosis by itself, notes Quora user. It's in the bottom few percentiles of the population, requiring more time to grasp complex concepts but not necessarily severe impairment.
In reviewing the evidence of both explanations I have found that it is a mix of both genetics and cultural upbringings. Though many humans must deal with violent situations as children and experience horrific events many do not become mass murderers.
As shown in the graph below, the prevalence of violent behavior dropped steadily with increasing IQ: 16.3% of individuals with IQs in the 70-79 range reported violent behavior, compared with just 2.9% of those with IQs of 120-129.
The targets of hate crime
Of the 11,679 hate crimes reported: 5,866 were on the basis of race. 3,004 against Black people. 797 against Latinx people (the second highest ever recorded).
In 2023, there were 14,327 murder offenders in the United States who were male, in comparison to 1,898 who were female. However, there were also 5,279 murder offenders where their gender was unknown.
I figure it's got to be a combination of things, first of all, and all kinds of things can make a serial killer. Physical and sexual abuse was the leading theory of FBI profilers for a long time. A lot of these guys grew up in very, very poor environments.
Actually, the Bible doesn't teach that murderers can't be saved in the normal way. Rather, it assures us that even they can receive salvation in Christ if only they repent of their sins and turn to Christ in faith. Some notable biblical examples include King David (2 Sam. 11-12) and the apostle Paul (Acts 8:1; 9:1).
However, very few serial killers are considered mentally ill enough to be declared legally insane. Rather, the majority display signs of psychopathy or sociopathy; in terms of diagnosis, they may meet the criteria for antisocial personality disorder.
True crime has never been more popular, especially among Millennials and Gen Z. We spoke to devoted fans and one of Britain's leading creators, True Crime Caitlyn, to uncover why these dark stories captivate a new generation.
In classifying types of serial murder, the factors discussed are behavioral background, victim profiles, methods used, and location of the murders. Four types of serial murderers are identified: the 'visionary,' the 'mission-oriented,' 'hedonistic,' and 'power/control-oriented.
The Heaviest Hitters
Slowness learning to talk, or continued difficulties with speech and language skills after starting to talk. Difficulty with self-help and self-care skills (e.g., getting dressed, washing, and feeding themselves) Poor planning or problem-solving abilities. Behavioral and social problems.
To calculate IQ, take a person's mental age, divide it by chronological age, and then multiply that number by 100. For example, if a person has a mental age of 12 but is 10 years old, then you'd divide 12 by 10, and multiply that number by 100, which would result in an IQ of 120.
Approximate IQ range of 50 to 69 (in adults, mental age from 9 to under 12 years). Likely to result in some learning difficulties in school. As adults individuals will be able to work and maintain good social relationships and contribute to society.
Taken together, heart diseases and cancers are the cause of every second death. In red are infectious diseases, which are responsible for around 1-in-7 deaths. These include pneumonia, diarrheal diseases, tuberculosis, HIV/AIDS, and malaria. A smaller share – around 4% – was from neonatal and maternal deaths.
Fox estimates there has been an 80% drop-off since serial killing peaked in the 1970s. At that time, there were nearly 300 known active serial killers in the US. A decade later, there were 250 active killers, who accounted for 120-180 deaths a year. In the 2010s, there were fewer than 50 known active killers.
Record numbers of men and women globally are now estimated to have reduced kidney function, a new study shows. Figures rose from 378 million people with the disease in 1990 to 788 million in 2023 as the world population grew and aged, making it for the first time a top 10 cause of death worldwide.