Why Your Childhood Has A Smell

A few weeks ago, I walked past a shop and caught a smell drifting out from inside.

I was not paying much attention. I cannot even remember what was displayed in the window. But before I could identify the smell or understand why it felt so familiar, I was suddenly back in kindergarten.

It was not like deliberately thinking about my childhood. I did not search through my memories or try to reconstruct what happened. The feeling arrived first. For a brief moment, something that had felt distant became close again.

Then the moment passed. I was still standing outside the shop, surrounded by the present, wondering how something as ordinary and invisible as a smell had reached a memory I had not visited in years.

Why could that scent return me to kindergarten, but simply looking at the shop could not?

When smell brings back more than an image

Psychologists call this the Proust phenomenon: the experience of a smell or taste unexpectedly unlocking a vivid autobiographical memory. It is named after Marcel Proust's description of tasting a madeleine dipped in tea and suddenly being transported back to his childhood.

What interested me was not that the smell made me remember: photographs, songs and familiar places can all remind us of the past. It was how little effort it required. I did not decide to remember kindergarten. The memory seemed to find me.

Research suggests that this is one of the unusual qualities of smell-evoked memory. Memories prompted by odours are often experienced as more emotional and more immersive than those prompted by pictures or words. In one study, Herz and Schooler (2002) found that memories recalled through smells were more emotionally powerful than memories connected to visual versions of the same cues. Participants also tended to feel more as if they had been “brought back” to the original moment.

A photograph may help us observe our past, but a smell can sometimes make us briefly feel as though we have stepped inside it.

Smell has a close relationship with emotion and memory

Part of the explanation lies in how smell is processed by the brain.

When we inhale an odour, receptors in the nose send information to the olfactory bulb. Olfactory information has close connections with areas involved in emotion and memory, including the amygdala, which contributes to emotional processing, and the hippocampus, which is important for forming and retrieving episodic memories.

This does not mean that smell has a magical doorway into memory, or that our other senses are disconnected from emotion. But the anatomy of the olfactory system may help explain why a scent can produce an emotional reaction before we have consciously identified what we are smelling. Neuroimaging research has also found that, compared with verbal cues, odour cues produced greater activity in medial temporal and limbic regions involved in autobiographical and emotional processing (Arshamian et al., 2013).

In other words, sometimes the brain appears to recognise the emotional meaning of a smell before we can find the explanation for it.

So why do smells often take us back to childhood?

There may also be something distinctive about the age of the memories that smells retrieve.

Willander and Larsson (2006) compared autobiographical memories triggered by odours, pictures and words. They found that smell-cued memories were more likely to come from the first decade of life, whereas memories prompted by pictures and words were more focused in adolescence and early adulthood.

One possible reason is that we repeatedly revisit visual memories. We look at childhood photographs, tell family stories and describe important events until they become familiar narratives. Each time we retell them, we reconstruct them.

Smells are difficult to describe and often remain in the background of an experience. We may not consciously think, I need to remember the scent of this classroom. Yet the association between that smell, the place and the emotion can remain. Years later, encountering it again may reactivate something that has not been put into words.

Perhaps that is why the memory outside the shop felt both unfamiliar and deeply mine. I had not forgotten kindergarten. I simply lost conscious access to that route back to it.

A powerful memory is not necessarily a perfect one...

However, there is an important distinction between a memory feeling real and being accurate.

Human memory is reconstructive. We do not store perfect recordings of our experiences and replay them unchanged. Every act of remembering is shaped by our present emotions, expectations and knowledge. A smell may intensify the vividness of a memory, but that emotional force does not guarantee that every detail is correct.

Smell is therefore not universally “better” than sight at remembering. Vision is extremely important for recognising people, objects and places, and visual cues may sometimes help us retrieve information more efficiently. The special quality of smell is not that it always produces faster or more accurate recall. It is that certain smells can make autobiographical memories feel unusually involuntary, emotional and close.

The invisible parts of our past

My encounter outside the shop lasted only a few seconds. Nothing around me had changed, but internally, the wall between my present self and my kindergarten self collapsed.

It made me wonder how much of our past remains attached to sensations we no longer notice: the smell of a classroom, a family member's cooking, an old book, rain on a familiar street or a product that is no longer part of our lives.

We often imagine memory as a collection of pictures. But perhaps some parts of our lives are preserved less like photographs and more like scents difficult to describe, but capable of returning when we least expect them.

References

Arshamian, A., Iannilli, E., Gerber, J. C., Willander, J., Persson, J., Seo, H.-S., Hummel, T., & Larsson, M. (2013). The functional neuroanatomy of odor evoked autobiographical memories cued by odors and words. Neuropsychologia, 51(1), 123–131. https://doi.org/10.1016/j.neuropsychologia.2012.10.023

Herz, R. S., & Schooler, J. W. (2002). A naturalistic study of autobiographical memories evoked by olfactory and visual cues: Testing the Proustian hypothesis. The American Journal of Psychology, 115(1), 21–32. https://doi.org/10.2307/1423672

Willander, J., & Larsson, M. (2006). Smell your way back to childhood: Autobiographical odor memory. Psychonomic Bulletin & Review, 13(2), 240–244. https://doi.org/10.3758/BF03193837