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  • Print publication year: 2010
  • Online publication date: June 2012

9 - Environmental Effects on Intelligence


More of your conversation would infect my brain.

Shakespeare, Coriolanus, act 2, scene 1

Shakespeare was right (again). Every experience we have leaves an imprint on our brains, and from it, on our minds. Clearly physical experiences can change the brain. It has been claimed that early species of Homo got a leg up on the evolutionary ladder when they began to eat fish. In modern days, lecithin, a substance found in a number of foods, including fish and eggs, has been studied to see if it can enhance learning. (The results are mixed.) We do not stop there; we concern ourselves with the social environment. If we do not believe that social experiences can affect the brains of children, why do we have decency ratings for movies and television programs? And why would it be possible to sell video programs for infants with names like Baby Einstein? How might we manipulate the environment to improve intelligence?

There are two ways this question can be interpreted. The less interesting interpretation is “Can the environment be manipulated to improve test scores?” A more interesting question is “Can the environment be manipulated to improve general mental competence?” The answer to both questions is “yes.”

Environment is a catch-all term. In discussing environmental effects on intelligence it is useful to make a distinction between the physical environment and the social environment. The physical environment involves things like nutrition, air pollutants, and disease – anything that makes itself felt by direct physical action.