Final answer:
Laud Humphreys' method of collecting data in his tearoom trade study contravened the principle of respect for persons by deceiving participants and not obtaining their informed consent, violating their autonomy and privacy.
Step-by-step explanation:
Laud Humphrey's collection of data for his tearoom trade study under the pretense of being a lookout represents a violation of the principle of respect for persons. This principle is central to research ethics and emphasizes the importance of respecting the autonomy and privacy of research participants. The principle adheres to the ideal that individuals should be treated as ends in themselves and have the right to make an informed decision regarding their participation in research.
In the tearoom trade study, Humphreys did not obtain informed consent from the individuals he was observing, thereby deceiving them about his true identity and purpose. This deceit directly contradicts the principle of respect for persons, as the participants were not allowed to consent to be part of the study. The participants' autonomy and privacy were compromised, and they were used as a means to an end without ever being informed or consenting to it, which is ethically wrong according to Kantian principles and legal standards regarding research with human subjects.