Human infants are helpless. At first they can’t even support the weight of their own heads. Crawling and walking take months to master. Compare this with the sprightly newborns of other mammals, such as kittens and foals, up and about within an hour of their birth. There are several theories as to why human development is so protracted – among them that this extra time is required for the human brain to develop. This post side-steps such debates and focuses on 10 studies hinting at the surprising abilities of babies aged up to one year. The research digested below suggests the infant mind is far more sophisticated than you might imagine:
Babies can meet a person once and remember them for years
We begin with a study in which 3-year-olds watched two videos shown side by side, each featuring a different researcher, one of whom they’d met once, two years earlier. The children spent longer looking at the video showing the researcher they hadn’t met. This is consistent with young children’s usual tendency to look longer at things that are unfamiliar, and it suggests they remembered the researcher they’d met once, when they were aged just one. Of course the phenomenon of infantile amnesia means these early long-term memories will likely be lost in subsequent years.
Babies can tell a human from a zombie (or a monkey)
Six-month-old and 12-month-old babies viewed pictures of cartoon human faces. Some of the faces looked creepy because they had zombie-style goggle eyes. Just like adults, the 12-month-olds (but not the 6-month-olds) spent longer looking at the faces with normal eyes. The researchers think this shows that by age one, human infants experience the “uncanny valley” effect – an aversion to creatures that are “almost human”. Another study published in 2011 found that 3-month-olds preferred looking at human faces or bodies than the bodies or faces of non-human primates, suggesting they already had some knowledge of what humans look like.
Babies can fake cry
Last year a Japanese researcher captured on video an instance of apparent feigned distress by an 11-month-old. Hiroko Nakayama filmed two babies in their homes for 60 minutes twice a month, for six months. One baby only ever cried after displaying negative emotion. However, on one occasion, the other baby (“Infant R”) was caught on camera laughing and smiling, then crying suddenly and briefly, then displaying positive emotion again. “Infant R appeared to cry deliberately to get her mother’s attention,” said Nakayama, [then] she showed smile immediately after her mother came closer.”
Babies can tell the difference between a dirge and a happy tune
For this study researchers played music to babies through speakers located either side of a face. They waited until the babies got bored and started looking away, then they changed the mood of the music – either from sad to happy, or vice versa. This mood switch made no difference to three-month-olds, but for the nine-month-olds it was enough to rekindle their interest and they started looking again in the direction of the face.
Babies have artistic tastes
After nine-month-old babies had grown bored of looking at a Monet paintings, their interest was piqued by the sight of a Picasso. However, the reverse wasn’t true: after time spent looking at Picasso, the babies preferred to look at more Picasso than at a new Monet. The researchers aren’t sure why Picasso holds such appeal, but it may have to do with the greater luminance of his paintings.
Babies can predict your intentions
Research published in 2006 found that 12-month-old babies, like adults, showed anticipatory eye movements when watching someone placing toys in a bucket. That is, their eyes jumped ahead to the bucket as if anticipating the person’s goal. Six-month-olds didn’t show this ability, they kept their eyes fixed on the toys. “We have demonstrated that when observing actions, 12-month-old infants focus on goals in the same way as adults do,” the researchers said.
Babies can hear speech sounds that you can’t
As babies develop they become attuned to the speech sounds relevant to their native language. Before this happens, they can detect all phonetic contrasts in human speech, including those that adults in their culture cannot. Take the example of the /r/ and /l/ sounds in English, which Japanese adults struggle to distinguish. Prior to 6-months, Japanese babies can distinguish these sounds as reliably as a baby raised in an English home.
Babies can show contempt
A study from 1980 involved adults looking at videotapes of babies (aged up to 9-months) as they pulled various facial expressions in response to real life events, including playful interactions and painful injections. The adults were able to reliably discern eight distinct emotions on the babies’ faces, including: “interest, joy, surprise, sadness, anger, disgust, contempt, and fear.”
Babies rehearse words long before they can speak
For a study published this year, researchers scanned 7- and 11-month-old babies’ brains as the infants listened to speech sounds. The psychologists observed activity in motor-related parts of the babies’ brains, suggesting that the babies were already rehearsing how to produce the sounds themselves, even though most of them wouldn’t be able to speak for some months.
Babies understand basic physics
Human infants appear to arrive with prior expectations about how the world works. For example, a 2009 study found that 5-month-olds use basic cues to detect whether a material is solid or liquid, and having done so, they form expectations for how these substances will behave, such as whether they will pour or tumble, or whether they will be penetrated by a straw. “… these experiments begin to clarify the beginnings of naive physics,” the researchers said.
If you enjoyed this post, you might also like The Psychology of First Impressions, Digested.
Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.