Do you ever get the feeling that you have an instinctive understanding of the meaning of a word in another language, even if it's a language you've never actually spoken or been taught?

There's a reason this happens, and it's got something to do with the way our brains are wired. In fact, it's possible that when we're children, the wiring of our brains means we're even better attuned to understanding 'sound symbolism' than we are as adults, but we lose a lot of this ability as we get older and learn our first language, says Madhuvanthi Kannan, a postdoctoral scientist in neurobiology at Yale University in the US.

Writing in Scientific American, Kannan points out that in some word tests, the majority of us will actually be able to guess the correct meaning of unknown words when given two words and two meanings.

"The trend holds even for non-existent words. In a famous linguistic test, subjects almost always gravitate to the non-word 'baluma' to describe rounded shapes and 'takete' for more angular objects. If you think about it, there appears to be something inherently rounded about 'baluma', and sharp and pointed about 'takete'. Likewise… 'tobi' seems like an apt choice to depict big objects whereas 'kekere' is more fitting for smaller entities. In other words, the dimensions are ostensibly encoded in the sound of the words." (Original emphasis.)

But how does this happen? According to Kannan, in sound symbolism, the mere sound of a word is enough to give us a sense of its meaning, due to the way our mind maps sound to meaning. At its most basic, this is reflected in the movement of our mouths when we speak individual words.

"In domains such as big/small, sound symbolic words translate aspects of size to physical aspects of the vocal tract, a linguistic feature termed iconicity," writes Kannan. "When we say 'grand' (French, for large), for example, our mouth expands as if to mimic the size of the object we refer to, whereas, when we say 'petit', the vocal tract constricts, and the word plants an impression of a tiny object."

But there's more to it than that, according to a recent study that sought to examine the links between synaesthesia and sound symbolism. Synaesthesia is a phenomenon that affects approximately 1 percent of people around the world, where stimulus of one sensory or cognitive pathway leads to an involuntary response in another sense or cognitive pathway.

In the case of language, a synaesthete (someone who experiences synaesthesia) may hear a word spoken and automatically see a colour, or experience a taste or a smell. The cross-wiring in the brain that's responsible for synaesthesia is thought to be caused by an increased number of nerve fibres that connect otherwise discrete areas of the brain.

In the study, researchers found that both synaesthetes and non-synaesthetes were remarkably good at guessing whether unknown, foreign words in several languages meant either big/small and loud/quiet – although neither group was good at guessing between up/down and bright/dark.

But it turned out that the synaesthetes were better guessers than the control group, which suggests that synaesthesia and sound symbolism are somehow linked. "It is tempting to postulate that their increased sensitivity to sound symbolism, a process that links auditory and visual senses, emerges from the cross-wirings seen in synaesthesia," writes Kannan.

Future research will seek to examine these links further, but already it's thought that perhaps as infants we may all have cross-wired brains, and, like synaesthetes, possess a highly attuned grasp for the meanings inherent in sound symbolism.

"But as we specialise in our native language, these cross-connections wither away and we grow out of our sensitivity to foreign languages," writes Kannan. "Scientists postulate that in synaesthetes, on the other hand, the cross-wirings persist into adulthood, due to genetic mutations that interfere with the pruning process."