"I have worked at the Arizona Humane Society for ten years, and have seen the effects of the failure to spay and neuter your pets first hand" is an example of what part of an effective introduction?

Establishing your credibility to speak on the topic

Explanation:

The first part of an introduction when giving a speech or lecture is to establish your credibility to speak on that topic. This is important to get your audiences attention, it could be achieved by talking lightly about your credentials and experiences in that field. The statement "I have worked at the Arizona Humane Society for ten years, and have seen the effects of the failure to spay and neuter your pets first hand" is the speaker establishing his/her credibility to speak on the topic.

i believe the answer is:   psychological  experiment

in this experiment, wilhelm wundt became the first person that implement scientific method in analyzing the pyschological phenomenon.

due to this result, wilhelm wundt also able to make psychology to be acknowledged as a separate scientific field from biology.