Maturation and environmentalism

Summarize Fact Check

One of the most common apparatus used by psychologists to study infant crawling is the visual cliff. This cliff was first used with different types of animals as well as infants to measure depth perception. ^[3] Organisms are placed on a raised glass board. Under the glass, material is placed to give the effect of a floor on one side of the apparatus. On the other side, the material is taken away to give the effect of a drop, and a deep side. ^[3] When infants are placed on this apparatus, psychologists can study whether or not these infants, or other animals, have gained the skills needed to understand that the visual drop is dangerous, or if they still cross the drop point.^[3] If young infants can avoid the experimental drop while crawling, researchers can assume that the aversion to cliffs is innately learned, not learned through crawling experience or teaching.

In one study, it was found that the age an infant begins crawling, and not the crawling experience of an infant, determined whether they would cross or avoid the visual cliff. The infants with a later crawling start date avoided the cliff significantly more than infants with an earlier crawling start date.^[4] These observations indicate that there is a biological time clock that is intuitively teaching infants about depth avoidance, rather than crawling experience teaching them about avoidance. These conclusions are consistent with maturation theory. In another study, psychologists found that the crawling experience negatively affected infants who could not yet walk and were placed in walkers on the virtual cliff. In this study, too, the age when crawling began was a better indicator of whether the infant would avoid the cliff rather than his or her crawling experience.^[5] This lends evidence to the theory of maturation and innate age related steps in development, rather than external factors.

Studies using a real water visual cliff found that infants with greater crawling experience had an easier time avoiding the cliff than those with less experience. A water cliff is a visual cliff with water in the deep end of the apparatus, and can measure an infant's potential perception of danger, as well as sensitivity to water.^[6] The results indicating that crawling experience was a greater indicator of avoidance align with the environmentalism theory in that infants learn through experiences with their environment. Additionally, researchers have also observed that infants who have learnt avoidance through crawling carried this avoidance over to when they start walking, rather than having to relearn these skills.^[7] These carryover effects indicate that infants are learning and processing through interactions with their environment and can apply their learnings to other new situations.

It has also been observed that a mother's emotions, seen through facial expression, can sometimes regulate an infant's behavior. Infants were placed on a visual cliff with a clear drop, and were able to see their mothers' facial expressions. When the mothers expressed fear, fewer infants crossed the cliff, indicating that the mothers' expressions had an effect on their behavior, supporting the environmentalism theory. However, when infants were placed on a visual cliff with a hidden drop, many infants crossed regardless of their mothers' facial expressions.^[8] This lends credence to the maturation theory; infants innately understand crawling and do not take cues from their surroundings.