Dextrous thumbs a Darwinian advantage, study says

The capacity to grip implements using an "opposable thumb", shared by no other creature in the world, has acquired a new significance thousands of years after it gave mankind mastery of the planet, scientists have found.

The capacity to grip implements using an "opposable thumb", shared by no other creature in the world, has acquired a new significance thousands of years after it gave mankind mastery of the planet, scientists have found.

In the era of computer games and mobile phones, those with the niftiest thumbs have a Darwinian advantage. They win the games, they book the best restaurant tables, they get the dates.

The feature said to distinguish us from t he apes is now used to mark the slickest performers among the young from their sluggish peers. Research studies on people aged under-25 in nine cities around the world has shown that among the digits, the thumb is primus inter pares.

Text messaging, e-mailing and zapping electronic enemies has developed the thumb into the hand's most muscled and dextrous digit.

Dr Sadie Plant, founder of the Cybernetic Culture Research Unit at Warwick University and author of the study spent six months collecting data on hundreds of mobile phone users in cities including London, Beijing, and Chicago.

She observed that instead of jabbing at the keypad with an index or other finger, as older users were inclined to do, the under-25s used both thumbs operating at speed while barely looking at the keyboard.

Unlike fingers, thumbs were employed ambidextrously. "They used the absolute minimal movement – simply exerting pressure with the thumb rather than tapping at the phone," Dr Plant observed.

For reasons as yet unexplained, young people under 25 most often chose to use their thumbs over any other digit. There is no question that choice is having a clear effect on their physicality. "Thumbs are the new fingers," she said.

The finding provides new evidence that technology causes physical changes that previously happened over generations.