Do humans really have pheromones? Will it affect our behavior?

When it comes to pheromones, people usually associate them with the animal world. For example, male moths chasing female moths, or pigs showing special reactions to androstenedione during estrus. But have you ever thought that humans may also have this mysterious chemical signal? Don’t worry, let’s talk about the science behind this today.

Humans, the ‘scent experts’ among primates

Firstly, it should be noted that humans are the most “flavorful” species among primates. Our sebaceous and apocrine glands have a much larger number and volume than other primates, which means that the natural substances released from our bodies are more complex and diverse. These odor information give each of us a unique ‘odor fingerprint’.

However, unlike most animals, humans do not have a powerful secondary olfactory system like other animals. That is to say, our olfactory processing mainly relies on the primary olfactory system rather than the secondary olfactory system. However, recent research has shown that although we do not have a clear “olfactory switch” like insects, our olfactory system can actually perceive many subtle chemical signals.

What exactly is human ‘pheromone’?

Scientists believe that pheromones are chemical signals that can influence behavior or emotions. For example, Rodriguez et al. discovered genes related to the accessory olfactory system in the human body, which means that we may perceive the emotions, identity, and even health status of others through smell in certain situations.

According to Jacob and McClintock’s research, human “pheromones” can be divided into four categories: direct effect pheromones, priming pheromones, communication pheromones, and regulatory pheromones.

Direct effect pheromone: This type of pheromone can quickly trigger behavioral responses, like a “switch”. For example, a mother’s breast odor can immediately trigger a newborn’s “orientation response,” which is a natural, non learning behavioral pattern.

Initiating pheromones: These pheromones affect physiological processes within our bodies, such as when women live together, their menstrual cycles tend to synchronize. A study has found that certain substances in women’s armpits can affect each other’s menstrual cycles, and even cause menstruation to be advanced or delayed.

Communication pheromones: These pheromones can transmit more complex information, such as gender, age, and even emotional states. We can actually identify the gender of others through smell, and even distinguish ourselves from others’ body odor through smell. This pheromone is regulated by the human immune system (leukocyte antigens) and affects our preferences when choosing a partner.

Regulating pheromones: The function of these pheromones is not to trigger rapid behavioral responses, but to produce subtle changes at the emotional or cognitive level. For example, sweat secreted during anxiety or fear can affect our perception of others’ facial expressions and even our emotional responses.

Although the scientific community’s understanding of human pheromones is still deepening, it cannot be denied that the role of odors in interpersonal interactions is far more complex than we imagine. It not only affects our emotions, but may also subtly influence the behavioral choices we make.

Although we do not rely on pheromones for socializing or reproduction like animals do, their influence still exists. Perhaps next time, when you are suddenly attracted by someone’s scent at a gathering, you may want to think about whether these pheromones are quietly working?