Gibson And Walk - The Visual Cliff Flashcards
Aims
Aimed to investigate whether the ability to perceive depth is innate or if it is learnt through experience.
Context
Nativists - Believe that we are born with the capacity to perceive depth.
Empiricists - Believe that we acquire our abilities through our experiences.
Interactionists - Believe that depth perception is a product of both.
Procedures
A visual cliff model was made with a centre board with an adjacent shallow drop and a deep drop.
A total of 36 infants were used aged 6-14 months. All were able to crawl.
They placed the child on the centre board and then had the mother call the baby so that it would in turn cross the deep then shallow sides. Stress levels were measured.
Non-human animals such as chicks, kittens (also kittens reared in the dark) and rats.
Eliminated all possible extraneous variables.
Findings
All of the 27 infants that moved off the centre board crawled onto the shallow side at least once. Only 3 attempted to crawl over the deep side. Many of the infants crawled away from their mothers when they were prompted to move across the deep side.
Chicks, kids and lambs: Never stepped on the deep side
Rats: Used whiskers to navigate so were more open to crawling over the deep side
Kittens: Froze if they were placed on the deep side and showed preference to the shallow. Dark kittens had no preference.
Conclusions
The findings show that human children can differentiate depths, it does not prove the nativist view but certainly supports it.
Methodology
Lab experiment
May not be innate seeing as the children were 6-14 months
They learnt that the safety glass was safe
They only used infants that were available to them at the time
Some of the babies showed distress at not being able to get to their parents. May not have been ethically correct seeing as the study did not end human suffering.
Alternative Evidence
Schwartz - Used children aged 5-9 months and placed them on the deep side and measured heart rate. If they sensed the drop heart rate would rise 5 month children had no change, whereas 9 months children did.
Witherington - Noticed that children that could walk were more wary of the shallow side than children that were experienced crawlers were less afraid of the shallow side.
Bower - Showed children as young as 6 days old had some depth perception. Had a large disc that approached to within 20 cm and a small disc that approached to within 8 cm. The children were more distressed by the small disc. I they had no depth perception then the discs would provide the same retinal image.
