Easy as 1, 2, 3

Easy as 1, 2, 3
Dec 30th 2008 From The Economist print edition
People come into the world ready to count its wonders
Illustration by Jon Berkley

THE baby is just one day old and has not yet left hospital. She is quiet but alert. Twenty centimetres from her face researchers have placed a white card with two black spots on it. She stares at it intently. A researcher removes the card and replaces it by another, this time with the spots differently spaced. As the cards alternate, her gaze starts to wander—until a third, with three black spots, is presented. Her gaze returns: she looks at it for twice as long as she did at the previous card. Can she tell that the number two is different from three, just 24 hours after coming into the world?
Or do newborns simply prefer more to fewer? The same experiment, but with three spots preceding two, shows the same revival of interest when the number of spots changes. Perhaps it is just the newness? When slightly older babies were shown cards with pictures of household objects instead of dots (a comb, a key, an orange and so on), changing the number of items had an effect separate from changing the items themselves. Could it be the pattern that two things make, as opposed to three? No again. Babies paid more attention to rectangles moving randomly on a screen when their number changed from two to three, or vice versa. The effect even crosses between senses. Babies who were repeatedly shown two spots perked up more when they then heard three drumbeats than when they heard just two; likewise when the researchers started with drumbeats and moved to spots.
“One great blooming, buzzing confusion” was how William James, a 19th-century psychologist, described the way he thought the world looked to a newborn baby. But these experiments, and many others like them over the past few decades, have convinced researchers that, on the contrary, babies are born with many ways of making sense of what they see and hear. The trick is to use their love of novelty to work out what is happening inside their brains: when shown the same things repeatedly, babies’ eyes wander; when the scene changes, their gaze returns. That makes visible what to them constitutes a change in the world around them worthy of notice.
Glossary:
Wonders:maravilhas stare= gaze:encarar.olhar fixamente newborn:recém nascido
Household:doméstico instead of=rather than randomly: ao acaso perk(ed) up: ficar animado likewise=also:também bloom(ing):nascente, florescente novelty:novidade
Wander:vagar worthy of: valoroso, bom