<span>The correct answer is Changing climates and nomadic enemies forced them to resort to alternative forms of sustenance. Shifts in climate force transitions in lifestyle. Invasions by nomads also compelled them to seek other ways of sustenance. As a result, they had to return to hunting and gathering at times. </span>
I do agree with Chillingworth, it is definitely better not to keep a guilty secret because, in my personal opinion, keeping this kind of secrets is like swallowing a slow acting poison. This guilty secrets, when kept, make us behave in a way that might cause harm to others or to ourselves; in other words, keeping this kind of secrets allows the harmful, hurtful behavior, we are keeping within the secret, to continue.
If you decide to keep this kind of secrets, it immediately creates a barrier between you and the person who told you the secret, and eventually it would also create a barrier with the person that might be hurt by knowing what you have been told. It is actually better and almost a life rule, to live your life without having any secrets to keep at all and, also, to not do anything you can not tell the people you care the most or that later, as time passes by, you will regret.
