People in all walks of life consistently have unexplained and unprovoked rushes of emotions. This can manifest itself in many ways from being instantly attracted to someone you just met to having a feeling of suspicion or distrust. These intense situations are not normally consciously recognized and they are taken for granted as another aspect of life. Scientists think they may now have an explanation for these occurrences.

The conclusion of their studies though has not been agreed upon by everyone, but those that do stand by it claim these feelings are being caused by pheromones.

Although the existence of pheromones has been known for many years, there have not been any conclusive studies into their actual consequences in humans. This has been due to badly thought out experiments and trials or dubious biases by the people carrying out the study. This coupled with the shady advertising of some pheromone products have left the entire field in a state of disrepute.

However this could all be about to change with new research and trials that are emerging. Recent evidence from brain imaging scans shows that humans do actually respond to pheromones and as more evidence amounts more and more scientists are starting to come around to the idea that humans do use and respond to the effects of pheromones.

The ticking point in this whole discussion is when will we stop arguing over whether or not pheromones affect our behaviour but instead pin pointing exactly how they affect us.

Pheromones have been proven to have definite effects on animals. Experiments with various animals from moths to pigs show that sexual reactions can occur from the animal being introduced to artificial pheromone sprays. They do this in many ways by stimulating ovulation or some other part of the animals behaviour that is synonymous with sexual behaviour.

Even though this knowledge has been known for many years the scientific community did not acknowledge their affect on humans. This was due to a number of reasons including the bias that people liked to believe we are somehow fundamentally different from animals. This reason was not completely unfounded as many animals that use pheromones have an organ that is not present in the human body. In animals pheromones are detected by an organ known as the vomeronasal organ or VNO. This is normally located in the nose and detects pheromones in the air and passes them along to the brain.

Humans do have an organ similar to the VNO however there is no direct link between this and the human brain. Many scientists believe it is solely a leftover organ from a time before humans evolved past the need to use pheromones. This claim has only recently been questioned by the scientific community.

Studies done at Harvard University showed that electrical impulses did occur at the area where the VNO is located in humans upon been administered pheromones. In women these reactions where strongest when the pheromone androstadienone was introduced. Androstadienone is a testosterone related pheromone found in male sweat. A calming effect was also noted in almost all participants of the study.

Although humans do not a fully functioning VNO in the classical sense recent evidence shows that pheromones are being processed by the normal olfactory channels. Many pheromones have been found in nature that do not depend on a VNO to function and there have been documented cases of definite reactions to pheromones in animals without a VNO. In one study it was found that mice detect a certain pheromone through a dense cluster of nerves at the tip of the nose and not the VNO.

This behaviour though is not unique to animals. Ivanka Savic a neuroscientist from Sweden recently showed in a brain imaging scan experiment that androstadienone directly stimulates an area of the brain that is a controller of sexual stimulation.

Many scientists are now saying that even though you can generate the symptoms of sexual excitement in humans that it does not necessarily mean they will become sexually excited. Whether or not pheromones actually work in humans is still debatable and the truth will not be known until the scientific community embrace the project objectively. leaving aside long standing bias and preconceptions.