Pheromones: How We Learn About Each Other Through Scent

We often think of communication as making signals to each other through words or other sounds. But humans and members of other species can communicate in several different ways. One of the ways that animals share essential information that shapes how they interact is through pheromones.

There are many myths and misconceptions about pheromones. Some people think that they are not found in humans or that people have a specific sex pheromone. However, pheromones do exist in humans, and the science behind them is complex and ever-evolving.

What are pheromones? 

A pheromone is a chemical that one animal produces that can be used to communicate with another animal of the same species. This is not the same type of communication as humans do with words and language-based messages, but it can help one animal interpret the status of another and change its behavior accordingly.

Pheromones are actually a type of hormone. Unlike most other hormones, though, they are secreted outside the body. This means that they do not affect the behavior of the individual producing the pheromones but that of the individual on the receiving end. Pheromones can trigger many different types of behavior, such as sexual arousal, defensive behaviors, or searching for food.

Types of Pheromones

There are many different pheromones, which scientists group into four main types based on their release and function.

• Releaser pheromones are characterized by their triggering of immediate responses and their reliability. They are frequently linked to sexual attraction and are closest to the type of pheromones that people generally think of.
• Primer pheromones take longer to alter an animal’s behavior. They often influence reproductive processes in females, such as menstrual cycles and pregnancy.
• Signaler pheromones alter animals’ behavior by communicating important information, such as the scent by which a mother recognizes her newborn baby.
• Modulator pheromones can alter body functions like the menstrual cycle. These can also affect another animal’s mood or behavioral responses.

Pheromones in animals

Scientists first discovered the presence of pheromones in insects. It is easier to understand how these chemicals help insects communicate since their pheromone systems are more straightforward than mammals. Pheromones are often used as bait in insect control, attracting insects into traps.

Other mammals use pheromones, but their systems are far more complicated. Scientists believe that many mammals detect pheromones through a particular organ in the nose. This organ connects to the hypothalamus, the part of the brain which controls the autonomic nervous system. This system regulates functions we do not engage in consciously, such as hunger, thirst, sleep, and emotional responses.

Pheromones in Humans

Many people think that since we have discovered pheromones in animals, humans must also use this communication method. However, scientists are unsure whether this is the case. In humans, the organ which allows other mammals to sense pheromones does not seem to function. It has been shown to be present in fetuses but atrophies before birth.

Certain studies have shown evidence of pheromones in humans by showing that human hormones can change in response to different smells. However, other scientists have questioned the methods of these studies, and there is no conclusive evidence that humans use pheromones to send signals to each other.

One common myth is that pheromones are involved in human sexual attraction. This is often promoted by pills or other products claiming to use pheromones to increase attractiveness. There is no proof, however, that this is the case.

Evolving Understandings

The science of pheromones is continuously evolving. Some scientists believe that pheromones are definitely present in humans. In contrast, others say that there is no conclusive evidence of this. Scientists also continue to search for evidence of a human sex pheromone. One study has suggested that there may be a pheromone that elicits a turn-off response, implying that there might be a turn-on one as well.

Our understanding of human pheromones is so limited because it is very hard to research them. Unlike in insects, pheromones do not cause dramatic effects in humans. This leaves scientists to try and determine whether specific responses are elicited by pheromones or whether they are also affected by other factors like sight, sound, context, and past experience.