Interesting experiment which suffers from the problem that all psychology experiments have: based upon observations of college students. I've been around the block a few times and I definitely don't now perceive respectful people as weak.
That doesn't seem to be the case to me.
The GP was talking specifically about the experiment design. Surveys are also notoriously unreliable as sources of meaningful data. Not that either point discounts the value of the research, of course.