Ever you ever "smelt" fear?
It's often described when people encounter a situation that they find frightening. But what does fear smell of? Isn't fear something we can only feel?
It turns out that smell and fear are highly interlinked. Babies learn what to be fearful of, by the specific odour their distressed mothers emit. Not only that, even if a mother has a specific fear or phobia that occurred before pregnancy, her baby quickly learns the same fear too, just from the smell she emits when she is exposed to the thing she is afraid of.
Before you go questioning what this smell is that mothers make, its important to acknowledge that these experiments were carried out on rats where the mothers were taught to be afraid of the smell of peppermint. The author of the study Jacek Debiac said, "An infant rat is immune to learning information about environmental dangers. But if the mother is the source of threat information, what they learn from her produces lasting memories"
But it does go a way to explain how a traumatic experience for a mother can have a profound effect on her offspring, even though they have not experienced the original source of fear. Blocking the response of the amygdala, the area of the brain associated with emotion and the fight and flight response found the infant rats no longer learned the fear. What it doesn't explain, is why there is such a wide variation in how different children of traumatised mothers respond or why the effect is so long lived..
Our sense of smell and link to emotion is something that we may be able to use to help to determine more effective treatments for those who suffer from different types of anxiety disorders and phobias.
What we don't know is whether this is the same effect that we experience as a calming effect when we smell something familiar and pleasant. Smelling teenage boys socks is perhaps not to be recommended, but the scent of a loved one on an item of clothing such as a sweater or pillow case, is a way we can instantly connect with the person we associate with a particular smell.
“Intergenerational transmission of emotional trauma through amygdala-dependent mother-to-infant transfer of specific fear” by Jacek Debiec and Regina Marie Sullivan in PNAS. Published online July 28 2014 doi:10.1073/pnas.1316740111