WSJ reports ($) that the effect of a gene depends on the environment it’s exposed to. Several studies have shown, for example, that water-fleas will only grow hard-skull defenses if they are in waters with fish, that oak-tree caterpillars grow to resemble the food they eat, and that men with the “violence gene” only act violent if they were neglected or abused as children. My favorite example:

Last summer, Michael Meaney of McGill University, Montreal, and colleagues reported that a gene that shapes how fearful, jumpy and neurotic a rat is can be altered by how regularly its mother licks and grooms it. Maternal care changes the chemistry of a “neuroticism gene,” and the rat grows up to be mellow and curious. The genetic trait for neuroticism — deemed innate because scientists had found a gene “for” it — is reversible by environment.

I wonder how different working environments interact with our genes?