"Although the environments that humans live in today are vastly divergent from those of our early ancestors, our genes are mostly conserved."

Such a great point. We are still adapting to an increasingly and rapidly changing world. If I'm understanding your point here...our genetics have yet to "catch up" to the new stressors we face today.

This reminds me of Robert Sapolsky's description of the changing nature of stress. We've gone from living in a world of acute short-term stress related to real physical dangers...and into a world of long-term periods of stress that are (mostly) psychological/imaginary in nature.

"Perhaps because the threshold for scenarios to be anxiety inducing has significantly decreased over centuries, experiencing excessive anxiety has become increasingly common."

This is something I hadn't considered, and it makes total sense. We are more easily triggered into an anxious (fight-or-flight) state than before.

Do you think this has mostly do with the new environment we find ourselves in (work, traffic, Internet, etc.) or has something changed in the way we psychologically respond to stress...or perhaps both?