The conclusion does not assert that one event causes another kind of event. The conclusion concerns a feature (body size) that allegedly plays a role in mating decisions. Body size is not an event. Also, the premise doesn’t present a correlation between two events.

The conclusion, about “all societies,” is based on reports from university-age students and analyses of personal ads in newspapers. There’s no reason to think these students and people who place personal ads are similar in their preferences to people generally in all societies.

The evidence does not suggest that there are multiple factors that play a role in mating decisions. The conclusion also does not assert that body size is the only influence on mating decisions.

The conclusion is not about individual persons. And the evidence does not apply to “entire societies.” The evidence concerns reports from university-age students and analyses of personal ads in newspapers.

We don’t know that there were only a “very small number” of individual cases. The stimulus doesn’t tell us how many self-reports or personal ads the conclusion is based on.