It has long been expected that what a mother eats during pregnancy is directly related to the type of food her child will be attracted to. In a recent study, newborn babies were subjected to two swabs of amniotic fluid (the fluid that protects and provides nutrients for a baby). You can see in the video below, babies actually “inhale” and “exhale” this fluid.
The researchers found that the babies are consistently positively biased towards the amniotic fluid it developed in. It shows that the human fetus is capable of detecting and storing olfactory stimuli, even before their brains are fully developed. This could be because olfaction is an evolutionarily old sense, developing sooner in fetuses than senses that rely heavily on the neocortex.
A side note, during this experiment, the researchers noted that the amniotic fluid of smoking mothers actually smelled like smoke. Rather disturbing, and the idea of fetal olfactory detection and storage could have implications in the study of high levels of nicotine dependance.