How smell contributes to interpersonal relationships: the influence of scents and odors in social dynamics

The sense of smell has long been considered a “secondary” sense compared to sight and hearing in understanding the human social behaviors. However, contemporary research in cognitive neuroscience, social psychology and evolutionary biology is progressively reevaluating its importance. Smell is not limited to perception of environmental odorsbut actively participates in building interpersonal relationships, as friendly as they are loving, influencing attraction, trust, emotional memory and social dynamics.

Its action is often unawarebut deeply rooted in the neurobiological processes that regulate emotions and social behavior.

What is social olfaction

From the point of view neuroanatomicalThe olfactory system has a direct connection with limbic structures such as amygdala and hippocampusinvolved in emotion processing and autobiographical memory, respectively.

This peculiarity explains why smells have such a powerful and immediate evocative capacity. In evolutionary terms, smell has played a fundamental function in the survival of mammals, facilitating the recognition of food, predators and different species.

In the human being, despite having lost part of the adaptive centralityretains significant relevance in the processes of “social recognition” and unconscious evaluation of others, judged based on their smell.

Smell and interpersonal attraction

One of the most studied areas concerns the role of smell in partner selection. Classical Studies in evolutionary psychologylike those on the greater than complex histocompatibility (MHC)suggest that individuals tend to prefer the smell of people who are genetically different from themselves.

When we talk about MHC it is no less than of the set of genes involved in the immune responsewhich influence indirectly body odor through the composition of secreted proteins and metabolites (for example in sweat). These molecules are then transformed by skin bacteria, producing specific odor profiles.

Claus Wedekind’s experiment “sweaty t-shirts”for example, showed that the women rate the smell of men with an MHC different from their own as more attractiveindicating a possible unconscious mechanism oriented towards genetic diversity and the immune robustness of the offspring. This kind of olfactory attraction it operates outside of awareness, suggesting that affective choices are not exclusively driven by cognitive or aesthetic factors.

Friends, mothers and babies: chemical communication between people

Smell also contributes to forms of chemical communication between peopleoften defined as chemosignaling. Although the scientific debate on the existence of human pheromones is still open, numerous evidence indicates that body odors can convey emotional information relevant.

For example, experimental studies have shown that exposure to sweat produced in conditions of fear it can induce an increase in physiological activation and a more cautious interpretation of environmental stimuli in observers.

This phenomenon is linked to theories of emotional contagion and embodied simulationaccording to which the emotional states can be shared and “mirrored” between individuals through sensory channels, including olfactory ones.

Furthermore, smell would seem to play a crucial role in the development of primary emotional bonds. In the newbornsthe ability to recognize the maternal smell contributes to the formation of the attachment bond, providing an immediate sense of security and continuity.

Similarly, in adults, the smell of familiar people can activate responses of comparison and stress reduction, smell functions as an implicit social recognition system, which facilitates the identification of ingroup (group to which you belong) e outgroup (group other than one’s own) quickly and pre-cognitively.

Does it smell or smell? The social construction of smell

Beyond theories, smell enters social relationships in a concrete way, often through common and embarrassing situations: “smelling bad”, sweating, or even simply making a “fussy” in public.

These episodes, completely natural from a physiological point of view, are however strongly regulated by implicit social norms. The so-called “stink” is not just a chemical issue, but quickly becomes a moral and relational issue: it can generate shame, distance or judgement, because it signals a breakdown in expectations of body control.

But the distinction between “perfume” and “stink” does not depend on an absolute intrinsic quality of substances, but on how our olfactory system and brain process them. On a biological level, odorous molecules are picked up by specific receptors in the nose, each sensitive to certain chemical characteristics (such as molecular structure and volatility).

These receptors send signals to the brain, where they are integrated and interpreted. However, it is above all at the brain level that the meaning of the smell is constructed: areas such as the amygdala and the orbitofrontal cortex associate olfactory stimuli with emotions, past experiences and cultural context.