Science Forums 2

[CraigD]

Originally Posted by Jet2

When I play with some babies, they seems to know what I think and response to me.

It’s important, I think, to comprehend how profoundly different infants think and perceive than slightly older children and adults, to avoid falling into a common variety of the anthropomorphic fallacy. Even though they are human, and in short time develop adult human thinking and perception, in their first months of life, as best the somewhat iffy science of early child development can tell us, babies are some bizarrely weird sensing and thinking machines!

Infants can perceive objects effectively at birth. Weirdly, their two eyes don’t truly move together to give proper stereoscopic vision, and their focus isn’t under voluntary control, causing their visual world to swim in and out of focus at roughly arm’s length distance, but with the proper set-up, they can track large, bright objects. It’s possible to detect, in a repeatable, systematic way, when an infant is startled by the sudden, unexpected appearance of an object in their vision. This gives us what we need to conduct this famous experiment, which resembles a very simplified stage magic show:

Set up a barrier, behind which an assortment of objects are concealed.
With an infant watching, pass an object behind the barrier, revealing them again as they emerge from the other side. After a few repetitions, switch objects behind the barrier to a different one emerges on the other side. Measure infant’s reaction.

Infant won’t show a surprise reaction. We can conclude that he/she doesn’t find object changing size, shape, and color anything out of the ordinary

Repeat the experiment at a later date, however, and Infant will show surprise, or even alarm. Sometime between the two experiments, he/she has “acquired a conservation perceptual schema”, and now expects objects to retain their characteristics when momentarily out-of-sight.

Variation of this experiment use images of peoples faces (babies are born with surprisingly sophisticated face-recognizing abilities), with similar results. Up to a certain age, multiple images of the same person doesn’t surprise Infant, then, fairly suddenly, when he/she has started to acquire the “there’s only one of each person” schema, sights contradicting this rule are surprising, even frighteningly so.

A person who has no expectation that a simple object will retain its characteristics pretty clearly isn’t cognitively capable of “thinking” about simple objects in a way much like an adult does, and is even less able to think about complicated objects like people, or guess at what people are thinking.

There’s pretty good evidence that even after a child has mastered the perceptual schema needed to understand the physical world well enough to search for specific hidden objects, play ball, and other sophisticated tasks, and understand and express themselves with language, they have limited ability to model the thoughts of others enough to even handle simple other-modeling tasks such as the very important, practical “If I do this, what will he do” prediction.

With the exception of children with neuropsychological disorders, such as some of those in the autistic spectrum, the perceptual and cognitive skills necessary to “know what others are thinking” (or, more corretly, make good guesses about it based on current and remembered sensory data) are pretty well developed within a few years of life.

The mental universe of a young infant, however, appears to be very alien to those you and I experience. Though it’s harmless, and extremely common, for adults to not understand this, it’s important that students of neurology and psychology learn that the commonplace assumption that babies “think” much like we do, and are limited only in their ability to express their thoughts, by best scientific theory and evidence, appears very incorrect.