Does the fact that medical researchers get money from drug manufacturers affect their results? The New England Journal of Medicine published a paper that included the following results. 15 The table...

Does the fact that medical researchers get money from drug manufacturers affect their results? The New England Journal of Medicine published a paper that included the following results.¹⁵
The table at the top of the next page summarizes the tone of articles published by 69 authors during 1996–1997. The publication was labeled either supportive, neutral, or critical. For each author, the data show whether the researchers received support from a pharmaceutical company.

(a) Do the data support the claim that by supporting research, drug companies influence the results of scientists?

(b) Does the table show a plain relationship, or might another variable lurk in the background? What might be its impact? Explain.