Which of the following methods is best suited for studying whether American parents are warmer than Japanese parents?

Compared to deaf adults exposed to sign language from birth, those who first learn sign language as teens are less likely to:

a. correctly imitate the signs they are shown. b. use signs to indicate concrete objects. c. mentally associate signs with written words. d. comprehend grammatical subtleties of sign language.

The following are all examples of pseudoscience tactics EXCEPT

A) creation of a "phantom" goal. B) vivid testimonials. C) manufacturing source credibility. D) the surplus heuristic.