Philosophy, Logic, and Rationalism
Correlation does not imply causation. Sometimes corr(X,Y) means X=>Y; sometimes it means Y=>X; sometimes it means W=>X, W=>Y. And sometimes it's an artifact of people's beliefs about corr(X, Y). Less Wrong: Self-fulfilling correlations
Dynamic inconsistency In economics, dynamic inconsistency, or time inconsistency, describes the situation: A decision-maker's preferences change over time, in such a way that a preference, at one point in time, is inconsistent with a preference at another point in time. It is often easiest to think about preferences over time in this context by thinking of decision-makers as being made up of many different "selves", with each self representing the decision-maker at a different point in time. So, for example, there is my today self, my tomorrow self, my next Tuesday self, my year from now self, etc. The inconsistency will occur when somehow the preferences of some of the selves are not aligned with each other. One type of inconsistency is more closely affiliated with game theory, and "dynamic inconsistency" is the more commonly used terminology in this case.
The Lucas critique, named for Robert Lucas' work on macroeconomic policymaking, argues that it is naive to try to predict the effects of a change in economic policy entirely on the basis of relationships observed in historical data, especially highly aggregated historical data. The basic idea pre-dates Lucas' contribution (related ideas are expressed as Campbell's Law and Goodhart's Law), but in a 1976 paper, Lucas drove to the point that this simple notion invalidated policy advice based on conclusions drawn from large-scale macroeconometric models. Because the parameters of those models were not structural, i.e. not policy-invariant, they would necessarily change whenever policy (the rules of the game) was changed. Policy conclusions based on those models would therefore potentially be misleading. Lucas critique
Introduction - Download - Tutorial - Details & Options - Donate Brain Workshop is a free open-source version of the dual n-back brain training exercise. What if a simple mental exercise could improve your memory and intelligence? A recent study published in PNAS, an important scientific journal, shows that a memory task called dual n-back improves working memory (short term memory) and fluid intelligence.
Practical Ethics A study published last week (and summarized here and here) demonstrated that a computer could be trained to detect real versus faked facial expressions of pain significantly better than humans. Participants were shown video clips of the faces of people actually in pain (elicited by submerging their arms in icy water) and clips of people simulating pain (with their arms in warm water). The participants had to indicate for each clip whether the expression of pain was genuine or faked. Whilst human observers could not discriminate real expressions of pain from faked expression better than chance, a computer vision system that automatically measured facial movements and performed pattern recognition on those movements attained 85% accuracy. Even when the human participants practiced, accuracy only increased to 55%. The authors explain that the system could also be trained to recognize other potentially deceptive actions involving a facial component.
I've been thinking a great deal lately about how best to study moral judgment. Let me say a few things myself, but I hope others will be able to chime in and share ideas, especially since I'm in the process of designing some studies. What's best to measure? So far it seems most researchers focus on measuring something other than what we might call purely "evaluative judgments," such as whether someone did something good or bad. This seems right to me since these don't necessarily constitute judgments about whether an action is right or wrong, which is paradigmatically a moral verdict. Experimental Philosophy
On the issue of whether to help now vs. later, many reasonable arguments have been collected on both sides. For example, positive interest rates argue for helping later, while declining need due to rising wealth argues for helping now. But I keep hearing one kind of argument I think is unreasonable, that doing stuff has good side effects: