Most babies will start to point their fingers at things between 9 and 14 months of age.
Until now, not a lot has been understood about why it emerges at this developmental stage other than to prompt language learning, but researchers now think they know more about it than before.
They key is touch, and it's a significant finding because it is a previously-unknown building block of language.
Cathal O'Madagain at the École Normale Supérieure in Paris and a team of European experts write in the study's abstract, "Pointing gestures play a foundational role in human language, but up to now, we have not known where these gestures come from."
It was previously thought that pointing might begin in reaching, however O'Madagain and his team thinks differently.
"When reaching, [infants] have the fingers splayed out. You don't see the distinctive index finger sticking out."
Working on a hypothesis that pointing originates with the desire to touch, the team performed three experiments with people aged 18 months to adult.
"We found, first, that when pointing at a target, children and adults oriented their fingers not as though trying to create an "arrow" that picks out the target but instead as though they were aiming to touch it; second, that when pointing at a target at an angle, participants rotated their wrists to match that angle as they would if they were trying to touch the target; and last, that young children interpret pointing gestures as if they were attempts to touch things, not as arrows."
The researchers say, "These results provide the first substantial evidence that pointing originates in touch."
O'Madagain says, "This allows us to put together a very different account of the origin of pointing – which is that pointing comes out of exploratory touch,"
This enables the baby to explore 'joint attention' which is a developmental milestone where they are focusing on an object with another person.