Published: 24 June 2013

Time to think

In which direction does time travel? A research collaboration between the University of Surrey and Stanford University suggests that your answer may reveal insights into the interaction between language and thought.

Take four images, one depicting a teenager, one a senior citizen, one a baby and one an adult. Now place them in the correct order.

If you are an English speaker, you'd probably lay the pictures out in front of you with the pictures portraying the passage of time from left to right. That's just how Westerners tend to think.

It's such a powerful instinct, it seems almost disconcerting to learn that this is not the universal human method for depicting time's arrow. Although all languages seem to resort to spatial metaphors to describe the inherently indescribable concept of time, in some cultures people would not tend to place the pictures left-to-right in chronological order. Some languages don't have easily translatable words corresponding to directional terms that are relative to the speaker's current alignment - in other words, English's basic 'right' and 'left' - and some don't use the same absolute or cardinal direction terms as our north, south, east and west. Most people see the future ahead and put the past behind them, but Aymara speakers from the Andes highlands reverse this, perhaps reasoning that we cannot see what lies in the future.

This wonderful complexity in representations of space and time offers endless insight into a fascinating question: does language affect thought?

In an article recently published in Frontiers In Cultural Psychology, Dr Sebastian Fedden of the Surrey Morphology Group and Professor Lera Boroditsky of Stanford University report on an experiment in which they asked speakers of Mian to complete 'non-linguistic temporal reasoning tasks' similar to our baby-to-senior-citizen test. Mian is the language of the Mianmin people in Papua New Guinea, a country noted for its astonishing linguistic diversity. The Mianmin are subsistence farmers living in a mountainous land of rainforests and rivers that is so remote and roadless it can only be reached on foot or by air.

In place of directional terms that are relative to the speaker's position or orientation, Mian uses a system of absolute spatial terms that derive from the Hak and Sek rivers, which flow broadly in parallel and roughly from east to west through the Telefomin District where the Mianmin live. The three key terms are met (meaning 'upriver'), tab (meaning 'downriver') and tām (meaning 'sideways from the river'). So where we might say 'the schoolhouse is to our left', in Mian one might say skul am met, or 'the schoolhouse is upriver'. This does not necessarily mean that the school is on or even near the river, merely that it is broadly upriver from us. If we were to turn around, in English we would have to change our phrase to 'the schoolhouse is to our right', but in Mian no such change would be necessary as neither the school's location nor the direction of the rivers' flow has altered.

How does this affect the way the Mianmin handle our non-linguistic temporal reasoning task?

"It turned out that some Mian speakers consistently laid out these sequences aligned with the local river," says Dr Fedden, whose reference work A Grammar of Mian recently won the prestigious Gabelentz Award from the Association for Linguistic Typology. "The river plays a very important role in Mian spatial reference. This shows that linguistic practices - in this case the upriver-downriver distinction - have an impact on mental processes."

What happens when someone speaks Mian far away from the rivers? It doesn't really come up. The language is only spoken by the Mianmin people, who number around 1,400, and is confined by geography and culture to a small area of Papua New Guinea. If you get too far from the rivers to know which way is upstream you'd be in a different language territory anyway.  (Younger Mianmin tend to know English, while older male Mianmin know the Telefol language of their neighbours and most Mianmin also speak the New Guinea variety of Neo-Melanesian Pidgin called Tok Pisin.) Hence the rivers are almost always intimately, physically present when people are speaking Mian.

Is this an unusual case of people's thought being shaped by their environment? Not according to Dr Fedden and Prof. Boroditsky. They contend that English's use of left-to-right terms is just as influential on thought processes, and possibly more bizarre than Mian's upriver-downriver scheme.

After all, if you think that time always runs from your left to your right, it follows that you can make time flow about you like a closely twining tango partner every time you turn around. The idea that time moves in one absolute and unchanging direction seems somewhat less bizarre in comparison, and perhaps even a little less egotistical.