Science news always slows down in December due to the holiday season. It’ll pick up again next year.

• Easily the most important article this month is this one about personality differences between men and women. Most people instinctively believe the sexes do tend to vary psychologically but the scientific consensus usually emphasizes that variances between individuals far outweigh general differences between the sexes. However more modern research now shows that there are in fact very significant differences between the sexes on narrower facets of personality and it is possible to predict whether a given person is male or female based on an overall personality profile. This suggests that the popular folk wisdom may be more justified than the previous politically correct scientific consensus.
• Next is a paper that revisits the by now well known Flynn effect which describes that the average IQ of people are increasing over time. This paper however claims that this generalization masks important differences such as that over various age groups. Tellingly, it also seems that those with already high IQ saw gains over time but those with low IQ saw drops. The most important conclusion is that we need to measure larger samples from more countries before we can meaningfully talk about how IQ changes over the course of decades.
• Then there’s this economics paper whose finding isn’t that all that interesting: giving medical insurance to people who previously lacked it reduces mortality. What is interesting is that the finding is based on a natural experiment that came about as a side effect of government policies. When the Obama administration wanted to penalize those who lacked health insurance, they found that their budget wasn’t enough to send letters to everyone. So instead they randomly chose people to send those letters to, inadvertently resulting in a randomized set of people in whose lives the government intervened to convince them to get insurance. This allowed the researchers to compare their outcomes with similar people who could have and did not receive the letters as a control group.
• This last one probably counts as an economics paper as well. We all know about NIMBYism, here specifically referring to the phenomenon of residents of a locality systematically opposing any new construction of residence in their neighborhood. We naturally expect this attitude from homeowners but this paper shows data that renters share similar attitudes. Even though they support more construction of residences overall, they oppose new construction in the neighborhoods that they themselves stay in. This demonstrates how difficult it is to solve the problem of rising housing costs in major cities when the only real solution is to build more housing.