Your letters.

This document is a collection of letters from readers of New Scientist magazine. The letters cover a range of topics, including the aggression of bonobos compared to chimps, the need for social change to reduce anxiety in children, the demographic problem of falling birth rates, the interpretation of quantum decisions, the impact of arthritis on aging, the benefits of spending time alone, the state of marine conservation in the UK, and the role of pheromones in human behavior. The letters provide diverse perspectives on these subjects and offer insights and suggestions for further exploration. [Extracted from the article]