Babies have logical reasoning before age one

Deductive problem solving was always thought to be beyond the reach of human infants. But now we find babies are capable of problem solving as early as 10 months of age.

According to a new study by psychologists at Emory University and Bucknell University, and published in the journal Developmental Science, research shows that babies can make inferences about social hierarchy and dominance.

"We found that within the first year of life, infants can engage in this type of logical reasoning which was previously thought to be beyond their reach until the age of about four or five years," says Stella Lourenco, the Emory University psychologist who led the study.

The researchers designed a non-verbal experiment using puppet characters. The experiment created scenarios among the puppets to test transitive inference, or the ability to deduce which character should dominate another character, even when the babies had not seen the two characters directly interact with one another.

A majority of the babies in the experiment, who were ages 10 to 13 months, showed a consistent pattern of transitive inference.

"If you can reason deductively, you can make generalizations without having to experience the world directly. This ability could be a crucial tool for making sense of the social relationships around us, and perhaps complex non-social interactions."

Stella Lourenco PhD, Psychologist, study leader, Emory University, Atlanta, Georgia, USA.

During the 1960s, developmental psychologist Jean Piaget showed that children could solve transitive inference problems around the age of seven or eight. For example, if you know that Paul is taller than Mary, and that Mary is taller than Jack, then you can infer indirectly that Paul must be taller than Jack. You don't need to see Paul and Jack standing side-by-side to draw this conclusion.

For years, the prevailing philosophy in cognitive psychology was that children younger than seven were mostly illogical and incapable of transitive inference - a form of intellectual reasoning by inferring outcomes based, with babies, on visual cues.

Then, during the late 1970s, researchers found that by reducing the complexity of transitive inference problems, children as young as four could solve them.

Lourenco's previous research had shown her that babies have numerical reasoning and can understand relationships of magnitude. So, she suspected they were also capable of transitive inference.

For the current study, Lourenco teamed up with co-authors Robert Hampton, an Emory psychologist whose lab at Yerkes National Primate Research Center has demonstrated that monkeys can engage in transitive inference, and Regina Paxton Gazes, a former graduate student in the Hampton lab and post-doctoral fellow at Zoo Atlanta.

Gazes, now on the psychology faculty at Bucknell University, designed the non-verbal experiments for the human infants.

In their control experiment with the infants, the hippo puppet always displayed dominant behavior and the elephant puppet always displayed subordinate behavior.

In the first video shown to the babies, the three puppets are arranged in a row. The elephant, bear and hippo, are similar in size but arranged in a left to right social hierarchy. The elephant is holding a toy, but the bear reaches over and forcibly takes the toy from the elephant. Next, the hippo takes the toy from the bear. This scenario suggests that the bear is more dominant than the elephant, and the hippo is more dominant than the bear.

Finally, the babies were shown a scenario where the elephant takes the toy from the hippo. This scenario held the gaze of most babies in the experiment longer than the other scenarios.

"Dominance by the elephant violates the expected transitive-inference relationship, since the bear took the toy from the elephant and the hippo took the toy from the bear.

"The babies looked longer and paid greater attention to the scene that violates the transitive inference as they try to figure out why it is different from what they would have predicted."

Stella Lourenco PhD

In a second experiment, the researchers introduced a fourth character, a giraffe, that had not yet interacted with the others in the familiarization phase of the control video. The giraffe being new, had not displayed dominance behavior. The infants did not pay any attention to scenarios involving the giraffe, whether or not it displayed dominance.

The data collected supported that the majority of the infants who were shown unexpected dominance behaviors, or 23 out of 32, were engaging in transitive inference when they gazed at scenarios of unexpected behavior by the puppets, compared to other scenarios.

The researchers hypothesize that transitive inference for social dominance is evolutionarily important, so the mechanisms to support this type of logical reasoning come into place early.

Gazes: "It's remarkable that the infants could make these inferences about social dominance with minimal presentation. It suggests an early emerging, and perhaps evolutionary ancient ability, that is shared with other animals."

In addition to exploring important science questions about how the mind develops, the findings could aid in determining whether infants are on track in the learning process.

Lourenco: "Since a majority of babies show the ability to engage in this kind of logical problem solving, our paradigm could certainly become an important tool for assessing normal cognitive development."

Abstract
It is surprising that there are inconsistent findings of transitive inference (TI) in young infants given that non-linguistic species succeed on TI tests. To conclusively test for TI in infants, we developed a task within the social domain, with which infants are known to show sophistication. We familiarized 10- to 13-month-olds (M = 11.53 months) to a video of two dominance interactions between three puppets (bear > elephant; hippo > bear) consistent with a dominance hierarchy (hippo > bear > elephant; where ‘>’ denotes greater dominance). Infants then viewed interactions between the two puppets that had not interacted during familiarization. These interactions were either congruent (hippo > elephant) or incongruent (elephant > hippo) with the inferred hierarchy. Consistent with TI, infants looked longer to incongruent than congruent displays. Control conditions ruled out the possibility that infants’ expectations were based on stable behaviors specific to individual puppets rather than their inferred transitive dominance relations. We suggest that TI may be supported by phylogenetically ancient mechanisms of ordinal representation and visuospatial processing that come online early in human development.

Research highlights
Deductive reasoning such as transitive inference (TI, e.g. if A > B and B > C, then A > C) has long been considered a prototypically logical process that requires linguistic representation and develops fairly late in humans.

We used a violation-of-expectation paradigm to determine whether infants inferred dominance relations between two puppets who previously interacted with a third puppet. We compared infant looking times to congruent (expected) and incongruent (unexpected) trials and found evidence of TI in infants 10–13 months of age.

Control conditions ruled out the possibility that differences in looking time were due to expectations about stable behavior of individual puppets rather than transitive relations among puppets.

Together with evidence from nonhuman animals, our results suggest that TI is supported by nonverbal, phylogenetically ancient ordinal and visuospatial processes.

Full article is available online at Developmental Science.

Related article:Parents smile at their babies because it's fun and rewarding — but a remarkable experiment reveals how important it also is to the child's developing mind and wellbeing. Read more at http://coach.ninemsn.com.au/2015/10/26/13/57/still-face-experiment#yZjWz0Tv114O8e5l.99  — The dark experiment that proves why smiling at your baby is so important

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Nov 27, 2015   Fetal Timeline   Maternal Timeline   News   News Archive   

Babies can discern who dominates who by about ten months of age.
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