One of the most significant factors keeping investors from reaching appropriate conclusions is their tendency to assess the world with emotionalism rather than objectivity. Their failings take two primary forms: selective perception and skewed interpretation. In other words, sometimes they take note of only positive events and ignore the negative ones, and sometimes the opposite is true. And sometimes they view events in a positive light, and sometimes it’s negative. But rarely are their perceptions and interpretations balanced and neutral.
...investor psychology rarely gives equal weight to both favorable and unfavorable developments. Likewise, investors’ interpretation of events is usually biased by their emotional reaction to whatever is going on at the moment. Most developments have both helpful and harmful aspects. But investors generally obsess about one or the other rather than consider both.
...It all seems so obvious: investors rarely maintain objective, rational, neutral and stable positions. First they exhibit high levels of optimism, greed, risk tolerance and credulousness, and their resulting behavior causes asset prices to rise, potential returns to fall and risk to increase. But then, for some reason – perhaps the arrival of a tipping point – they switch to pessimism, fear, risk aversion and skepticism, and this causes asset prices to fall, prospective returns to rise and risk to decrease. Notably, each group of phenomena tends to happen in unison, and the swing from one to the other often goes far beyond what reason might call for.That’s one of the crazy things: in the real world, things generally fluctuate between “pretty good” and “not so hot.” But in the world of investing, perception often swings from “flawless” to “hopeless.” The pendulum careens from one extreme to the other, spending almost no time at “the happy medium” and rather little in the range of reasonableness. First there’s denial, and then there’s capitulation.
“It’s kind of fun to sit there and outthink people who are way smarter than you are because you’ve trained yourself to be more objective and more multidisciplinary. Furthermore, there is a lot of money in it, as I can testify from my own personal experience.”As well as this excerpt from one of his speeches in Poor Charlie's Almanack:
Engaging in routines that allow you to maintain objectivity are, of course, very helpful to cognition. We all remember that Darwin paid special attention to disconfirming evidence, particularly when it disconfirmed something he believed and loved. Routines like that are required if a life is to maximize correct thinking. And one also needs checklist routines. They prevent a lot of errors, and not just for pilots. You should not only possess wide-ranging elementary wisdom but also go through mental checklist routines in using it. There is no other procedure that will work as well.