My impression is that optimism peaked in the '50s -- some time before I was alive -- and has been in decline ever since. That's not to say that there haven't be

My impression is that optimism peaked in the '50s -- some time before I was alive -- and has been in decline ever since. That's not to say that there haven't been major achievements since then -- I wouldn't have a career without them -- but increasingly, we have seen experts throwing up their hands and saying "I don't know how this will ever be solved". The most optimism right now comes from people who think major societal problems will be solved by machines that can solve more problems than people. That of course does not contradict the idea that humans are having more and more trouble solving our problems, even as we continue to move forward in the near term. We have never had a unified cultural perspective on this phenomenon -- it is either an artifact of regressive politics, a warning sign of the limits to growth, a reflection of deep failings in the basic structure of society, a punishment from Heaven for our disregard for tradition, or [choose as many as you like]. But as it continues to become more visible, the possible conclusions clash more and more. So while social media appears to create divisions in society, I don't think it's the only cause, and I don't think the only causes are things for which we can so easily allocate blame.