In a man.
The word "man" in scripture "anthropos" often refers to "mankind"= male and female.
Jesus was speaking in a parable referring to "a man" as a whole "wicked generation" this is clear.
Matthew 12:45
Then goeth he, and taketh with himself seven other spirits more wicked than himself, and they enter in and dwell there: and the last state of that man is worse than the first. Even so shall it be also unto this wicked generation.
A "generation" is defined how the Lord defines it, not how man sees it. For instance a "generation of vipers" is not talking about the offspring of physical serpents, but rather those who are of the Serpents seed as was mentioned in Genesis. We know by scripture that Cain was of "that Wicked" so this "wicked generation" being a "seed of evil doers" is not talking about a small group of people in a limited amount of time such as a "generation" as man knows it. There is also a "regeneration" to come.