Learning a concept without a word
Chapter 7 endnote 13, from Lisa Feldman Barrett.
Some context is:
...we distinguish the concepts “Plant” and “Human Being” without requiring words for them: plants photosynthesize and people do not. The difference is perceiver-independent, regardless of how the two concepts are named.
Some concepts can be learned without words. A fascinating example is the concept “solid, transparent surface,” which can be learned by infants.
If you give nine-month old infants an opaque container to play with (having a closed top, bottom, and side, and one open side), they will quickly find the opening and remove anything you have placed inside it, like a toy. If the container is transparent, however, infants rarely retrieve the toy because they try to put their hand through the transparent surface and can’t; they typically don’t search for the opening in the side. If you give the infant some prior experience playing with the transparent container at home, with no instruction, before they come to the lab, they very quickly retrieve the toy from the transparent box.
To demonstrate that these infant subjects have learned a concept for “solid and supporting surface, even when transparent,” the infants are then placed on a "visual cliff." This is a transparent surface placed over a visual drop, so that there is a “safe side” (where the surface appears solid) and a “vertical drop” (that contains the transparent but solid surface over a vertical drop). In the classic experience, eight and nine month old infants placed on the safe side will not crawl across the vertical drop. The infants who had previously played with the transparent containers, however, crawled across the visual cliff with no apprehension. This is clearly evidence of a learned concept, because transparent and solid surfaces are human artifacts and therefore this learning cannot be attributed to an evolutionary adaptation.
Learning not to crawl over a visual cliff is itself a concept that is learned with experience, but without the benefit of a word (e.g., infants without crawling experience plunge over the edge of a real cliff or a steep slope).
Notes on the Notes
- Smith 2010 [full reference to be provided]
- Diamond, 1990. [full reference to be provided]
- Titzer, 1997. [full reference to be provided]
- Walk, Richard D., and Eleanor J. Gibson. 1960. "The 'visual cliff.'" Scientific American 202 (4): 67-71.
- Walk, Richard D., and Eleanor J. Gibson. 1961. "A comparative and analytical study of visual depth perception." Psychological Monographs: General and Applied 75 (15): 1-44.
- Adolph, Karen E., Kari S. Kretch, and Vanessa LoBue. 2014. "Fear of heights in infants?" Current Directions in Psychological Science 23 (1): 60–66.