The speaker mainly discusses________.

Culture can be defined as behavior that is learned and transmitted to members of a group. A child learns a particular behavior through observation as well as through positive and negative feedback from his/her family and peers. A minor point to remember is that this feedback can be overt or covert. Much covert feedback involves nonverbal cues that an outsider to that culture would not understand.

There are exceptions to the rule of male insects being smaller than the females, and some of these exceptions are intelligible. Size and strength would be advantage to the males which fight for the possession of the females, and in these cases, as with the stag-beetle, the males are larger than the females. There are, however, other beetles which are not known to fight together, of which the males exceed the females in size. But in some of the other cases, as with the huge Dynastes and Megasoma, we can see that there would be no necessity for the males to be smaller in order to be matured before them, for these beetles are not short-lived.