Babies have logical reasoning even before age one

Thursday, Nov 19, 2015,16:26 IST By Metrovaartha A A A

Washington | Baby may be capable of making inferences and engaging in logical reasoning as early as 10 months of age, a new study has found. We found that within the first year of life, children 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, said Stella Lourenco from the Emory University in US, 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 each other. For the study, the babies, who were ages 10 to 13 months, were shown a video of three puppets arranged in a row.

The puppets – an elephant, a bear and a hippopotamus, were 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 hippopotamus takes the toy from the bear. The scenarios suggested 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 the babies in the experiment for 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, Lourenco said.

The babies look longer and pay greater attention to the scenario that violates the transitive inference as they try to figure out why it is different from what they would have predicted, she said. In a second experiment, the researchers introduced a fourth character, a giraffe.

The giraffe was novel and had not previously displayed dominance behaviour. The infants did not pay more attention to scenarios involving the giraffe, whether or not it displayed dominance. The researchers also conducted control experiments, where the hippo always displayed dominant behaviour and the elephant always displayed subordinate behaviour.

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

The researchers hypothesise that transitive inference for social dominance is evolutionarily important, so the mechanisms to support this type of logical reasoning are in place early. The study appears in the journal Developmental Science.