Getting children to play together cooperatively depends less on their social skills and more on the activity, especially when they are not already friends, a study shows. Researchers found that non-friends played more “in sync” when given a task to complete. In goal-directed play, their connectedness (cooperation and coherent communication) rose by about 25% compared with situations where they were just asked to play freely with toys. The findings suggest that if parents or teachers want children who are not friends to play collaboratively and positively, giving them a shared goal can encourage more cooperative behaviour.

New research reveals that extreme heat is literally changing the human population's sex ratio — but for two completely different reasons. A massive study of 5 million births in sub-Saharan Africa and India, published recently in PNAS, shows that hot days during pregnancy result in significantly fewer male births.

In sub-Saharan Africa, the cause is biological. Heat stress during the first trimester increases the rate of miscarriage. Because male fetuses are biologically more fragile, they are disproportionately lost to maternal heat stress.

In India, however, the cause is behavioral. Heat waves during the second trimester disrupt access to medical services and financial resources, inadvertently reducing the rate of sex-selective abortions (which typically target girls).

Co-authored by researchers including Portland State University's Joshua Wilde, the study highlights how climate change is quietly acting as both a biological filter and a disruptor of human behavior.

These days, transparency is a financial buzzword, but new research from Michael Sockin found that, in some cases, less transparency can lead to better economic outcomes.