Babies wise to what we really mean: Researchers find first evidence that six-month-olds comprehend adults' intentions

February 9, 2010

A study by York University researchers reveals that infants as young as six months old know when we're "playing" them - and they don't like it.

Researchers in York's Centre for Infancy Studies examined six-and nine-month-old babies' reactions to a game in which an experimenter was either unable or unwilling to share a toy. Babies detected and calmly accepted when an experimenter was unable to share for reasons beyond her control, but averted their gazes and became agitated when it was clear she simply wouldn't share.

"Babies can tell if you're teasing or being manipulative, and they let you know it," says study lead author Heidi Marsh, a PhD student who worked under the direction of psychology professor Maria Legerstee, head of the Centre for Infancy Studies in York's Faculty of Health.

"These results are exciting as it's the first demonstration that used infants' to successfully show that at six months they comprehend the goals of our actions. Previously, there was only evidence based on visual habituation (observing the pattern of infants' gazes towards stimuli) which is prone to interpretative issues, and even those results were very mixed," Marsh says.

Other studies have concluded that this ability doesn't develop until nine months of age. However, that research used measures which Marsh proposes are unsuited to younger infants.

"A six-month-old as compared to a nine-month-old has different ways of expressing what they know," says Marsh. "The innovative aspect of this research is that we used measures that are consistent with a six-month-old's everyday behaviour in order to understand what they comprehend. We recorded their social responses, such as sadness, gaze aversions, smiles and vocalizations, in addition to more physical responses such as reaching and banging," she says.

The study looked at 40 infants, evenly divided between genders. Infants sat in their mothers' laps at a table, with the experimenter seated across from them. In half the test trials, the toy was not passed to the infant because the experimenter was unwilling to share it, and in the others, it was not passed because the experimenter was trying, but unable, to pass it.

Infants were administered three tasks: block, mock, and play. Each task differed with respect to the toy that was shared, and the nature of the sharing game, but in all tasks there was a corresponding unwilling and unable condition. For instance, in the mock task, a rattle was held out toward the infant, and then pulled back teasingly (unwilling condition), and a ball was "accidentally" dropped and rolled back to the experimenter (unable condition).

The visible movements of both the experimenter and the toy were matched across conditions, as was the outcome that the toy was not shared. This meant that the main difference between conditions was the experimenter's intent.

"We also used the experimenter's facial expressions to convey unwillingness or inability, as they're important cues for babies to understand others' goals," says Marsh.

Infants at both ages averted their gazes during unwilling trials. They also reached more in the unable conditions, suggesting they understood there was a problem and were trying to elicit the adult's assistance. The nine-month-olds banged their arms in the unwilling conditions, whereas the six-month-olds showed more negative affect, such as frowns, in those trials, and positive affective behaviours in unable conditions.

"Our finding that affective measures are stronger for younger infants may be related to their level of independence," Marsh says. "As infants become more independent, they decrease affective behavior such as crying, and increase physical actions such as actively resisting. These distinctions point to the importance of studying infants' social and cognitive abilities not only over time, but also in paradigms that capture the spectrum of their social behaviours."

The study, "Six-and Nine-Month-Old Discriminate Between Goals Despite Similar Action Patterns," is co-authored by Legerstee, Jennifer Stavropoulos and Tom Nienhuis. It was published online in Infancy in January 2010.

This research was supported by grants from the Social Sciences and Humanities Research Council of Canada (SSHRC).

Related Stories

Recommended for you

Self-harm, suicide attempts climb among US girls, study says

November 21, 2017
Attempted suicides, drug overdoses, cutting and other types of self-injury have increased substantially in U.S. girls, a 15-year study of emergency room visits found.

Car, stroller, juice: Babies understand when words are related

November 20, 2017
The meaning behind infants' screeches, squeals and wails may frustrate and confound sleep-deprived new parents. But at an age when babies cannot yet speak to us in words, they are already avid students of language.

Simple EKG can determine whether patient has depression or bipolar disorder

November 20, 2017
A groundbreaking Loyola Medicine study suggests that a simple 15-minute electrocardiogram could help a physician determine whether a patient has major depression or bipolar disorder.

Non-fearful social withdrawal linked positively to creativity

November 20, 2017
Everyone needs an occasional break from the social ramble, though spending too much time alone can be unhealthy and there is growing evidence that the psychosocial effects of too much solitude can last a lifetime.

Cultural values can be a strong predictor of alcohol consumption

November 20, 2017
Countries with populations that value autonomy and harmony tend to have higher average levels of alcohol consumption than countries with more traditional values, such as hierarchy and being part of a collective. This new ...

A walk at the mall or the park? New study shows, for moms and daughters, a walk in the park is best

November 17, 2017
Spending time together with family may help strengthen the family bond, but new research from the University of Illinois shows that specifically spending time outside in nature—even just a 20-minute walk—together can ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.