Scholars have expressed concern that the introduction of substantial coverage of "medical genetics" in the mass media during the past 2 decades represents an increase in biological determinism in public discourse. To test this contention, we analyzed the contents of a randomly selected, structured sample of American public newspapers (n = 250) and magazines (n = 722) published during 1919-95. Three coders, using three measures, all with interceder reliability >85%, were employed. Results indicate that the introduction of the discourse of medical genetics is correlated with both a statistically significant decrease in the degree to which articles attribute human characteristics to genetic causes (P < .001) and a statistically significant increase in the differentiation of attributions to genetic and other causes among various conditions or outcomes (P < .016). There has been no statistically significant change in the relative proportions of physical phenomena attributed to genetic causes, but there has been a statistically significant decrease in the number of articles assigning genetic causes to mental (P < .002) and behavioral (P < .000) characteristics. These results suggest that the current discourse of medical genetics is not accurately described as more biologically deterministic than its antecedents.
