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What is the Big Brother effect?

The Big Brother effect, also known as the fraternal birth order effect, is a phenomenon that has intrigued scientists for decades. The effect describes the increased likelihood of a male child becoming homosexual based on the number of older brothers he has.

How Was the Big Brother Effect Discovered?

The effect was first observed in the late 1970s by a researcher named Ray Blanchard. He noticed that gay men tended to have more older brothers than straight men. Blanchard conducted a study in which he gathered data from more than 2,000 participants and found that male sexual orientation was strongly linked to fraternal birth order.

Other studies since that time have confirmed Blanchard’s findings. One such study, published in the Proceedings of the National Academy of Sciences in 2006, found that there was a 33% increase in the odds of a man being gay for each older brother he had.

What Causes the Big Brother Effect?

There are several theories as to what causes the Big Brother effect. One theory is that it is related to the mother’s immune system. According to this theory, when a woman has a male fetus, her immune system may produce antibodies that react with a protein that is essential to the development of the male brain. With each subsequent male fetus, the mother’s immune system produces more of these antibodies, which could interfere with the development of the fetal brain in a way that increases the likelihood of homosexuality.

Another theory is that the Big Brother effect is related to social factors. According to this theory, younger brothers with older brothers may be more exposed to male norms and may be more likely to identify with these norms and adopt a homosexual identity. Older brothers may also act as role models and influence younger siblings to adopt certain behaviors or identities.

What About Females?

The Big Brother effect is specifically related to male sexual orientation. There is no known effect related to the number of sisters a male has or the number of brothers or sisters a female has.

What Are the Implications of the Big Brother Effect?

The Big Brother effect has implications for our understanding of the biological basis of sexual orientation. It also has implications for people who are struggling to come to terms with their sexual orientation. Knowing that there may be a biological basis for homosexuality may help to reduce feelings of shame or self-blame that can be common in people who are struggling with their sexuality.

However, it’s important to note that the Big Brother effect is just one of many factors that can contribute to sexual orientation. There is no single “cause” of homosexuality, and it’s likely that there are a variety of genetic, biological, and social factors that contribute to an individual’s sexual orientation.


The Big Brother effect has been observed in multiple studies and suggests that the number of older brothers a male has can increase his likelihood of being gay. Possible explanations for this effect include both biological and social factors, but the exact cause is not yet understood. The Big Brother effect underscores the complex nature of sexual orientation and the need for continued research in this area.


What is the older brother effect in psychology?

The older brother effect, also known as the fraternal birth order effect (FBOE), is a phenomenon observed in psychology where the likelihood of a male having a homosexual orientation increases with each older brother he has. This effect has been researched extensively and has been found to be a consistent pattern across various cultures and environments.

The origin of the older brother effect is still somewhat unknown, but it is thought to be related to changes in the mother’s immune system during pregnancy. When a woman becomes pregnant with her first male child, her immune system is exposed to certain proteins produced by his developing brain. This exposure causes the mother’s immune system to produce antibodies to these proteins. When the woman becomes pregnant with subsequent male children, these same antibodies produced by her immune system have the potential to cross the placenta and enter the developing brains of her other male fetuses. It is believed that these antibodies may alter the developing brain in a way that increases the likelihood of the child being attracted to men.

Studies have consistently shown that the more older brothers a male has, the greater the likelihood of him being homosexual. For example, research has found that having one older brother increases a male’s chances of being gay by about 33%, while having two or more older brothers increases the likelihood by about 50%. Although the older brother effect is only observed in males, studies have also found that the mothers of gay males tend to have more children overall, a phenomenon known as the female fecundity effect.

It’s important to note that the older brother effect is not applicable to all cases of homosexuality, and many factors can contribute to a person’s sexual orientation. However, the effect is one of the most well-established findings in the research of sexual orientation. Further research is necessary to fully understand the underlying mechanisms of this effect and how it relates to sexual orientation.

What is big brother in criminology?

Big Brother is a term that originated from George Orwell’s novel “1984” which was published in 1949. It describes an authoritarian government that uses advanced technology to monitor its citizens’ every move. In criminology, the term “big brother” is used to refer to a type of surveillance system that tracks criminal activities in a society. The system is designed to provide government agencies with intelligence about the activities of criminals, including identifying crime patterns and potential threats to national security.

Big Brother surveillance systems usually consist of a network of cameras, sensors, and other monitoring devices that are strategically placed in public places such as streets, parking lots, airports, and other critical infrastructure. These systems allow security personnel to monitor suspicious activities and quickly respond to any threats to public safety.

The use of Big Brother surveillance systems is highly controversial as it raises concerns about privacy and civil liberties. Critics argue that the widespread use of surveillance technology can lead to abuse of power by government agencies. They also argue that the technology can be easily misused to target political dissidents and other individuals who may be innocent of any wrongdoing.

Despite these concerns, many governments around the world continue to use Big Brother surveillance systems to counteract crime and terrorism. The systems are seen as essential tools in supporting law enforcement agencies in maintaining public safety. Such crimes that are being monitored via these surveillance systems include bomb blasts, suicide bombers, random shootouts, and any other activities that are considered a threat to public safety.

The term Big Brother in criminology refers to a type of surveillance system that monitors criminal activities in society. While the use of these systems is controversial, they remain a critical tool for law enforcement agencies in maintaining public safety. It is important that the government employs these technologies ethically and transparently to avoid any abuse of power and safeguard individuals’ privacy and civil liberties.

What is oldest brother syndrome?

Oldest brother syndrome is a term used to describe the behavior and characteristics exhibited by the eldest sibling in a family. Typically, the eldest child takes on a leadership role within the family, guiding and nurturing their younger siblings. However, this role can sometimes lead to a set of behaviors known as oldest brother syndrome.

Some of the common signs of oldest child syndrome include an obsession with rules, a desire for perfection, and an overly developed sense of responsibility. Elder siblings often feel a great deal of pressure to meet their parents’ expectations, and as a result, they can be very hard on themselves. They may also take on too much responsibility, attempting to act as second parents to their siblings.

Children with oldest child syndrome may also exhibit a high degree of self-esteem, believing that they are always right and that their opinions carry more weight than those of their siblings. Additionally, they may become very dominant, seeking to maintain control over their younger siblings and often acting as though they know best.

While these characteristics can be common among eldest children, it’s important to remember that not all older siblings will exhibit them. Additionally, it’s important to recognize the positive aspects of being the eldest child in a family, including increased leadership skills and a strong sense of responsibility.

Oldest brother syndrome is a set of behaviors that can sometimes develop in the eldest child of a family. While it can be challenging for both the eldest child and their younger siblings, it’s important to remember that these characteristics are not set in stone, and with awareness and understanding, families can work together to build healthy and fulfilling relationships.