First, consider deliberate thinking. Deliberate thinking is relatively slow, rule-based and explicit; a contemplative process of weighing pros and cons, gathering scientific or statistical evidence. It would appear that this makes for pretty solid decision-making.
Jul 24, 2015. Outliers increase the standard deviation. Mean is most affected by outliers, since all values in a sample are given the same weight when calculating mean. A value that is far removed from the mean is going to likely skew your results and increase the standard deviation. Say you have five values: 2, 1, 2, 1.5, and 2.1.
If this curve were flatter and more spread out, the standard deviation would have to be larger in order to account for those 68 percent or so of the people. So that's why the standard deviation can tell you how spread out the examples in a set are from the mean.