I slunk into my social studies classroom with my head down. Graded homework assignments sat on the corner of my teacher's desk. As my fellow seventh grade students chatted before class began, I casually slid my late homework into the middle of the pile. When our teacher later distributed the papers, he would see mine was not graded, assume he'd missed it, and I'd be off scot-free. Indeed, my ploy worked like a charm.

Decades later I still reflect on that episode with a twinge of guilt. Understanding the reasons behind our dishonest behavior and how to curb our nature are the subject of microbiologists Ferric C. Fang and Arturo Casadevall's cover story, “Why We Cheat,” on page 30. One impetus they identified is fear—specifically, a dread of failure.

Extreme fear can override other moral intuitions, too. In a war zone, for example, a soldier's intense emotions may trigger a so-called predator mode. A combatant in this state of mind is less likely to view bloodshed as reprehensible or to experience psychological trauma as a result of battle. On page 46, “An Appetite for Aggression” describes some surprising findings—and their implications.

As scientists plumb our dark side, they are also discovering ways to shore up our cognitive weaknesses. Research on ADHD has led to computer games aimed at strengthening working memory, a skill that undergirds intelligence. See “Calisthenics for a Child's Mind,” by Mind editor Ingrid Wickelgren, on page 38.

We may also one day find ourselves buttressing our brain with therapies derived from two substances best known as illegal party drugs, psilocybin mushrooms and ketamine. In this issue's two-part special report, starting on page 58, we explore these drugs' unique effects on depression, addiction and other disorders.

Scientific American Mind has been growing and improving as well. Last month we launched a new home page—mind.scientificamerican.com—and unveiled a blog network. In print and online, we seek to bring you insights into the rich mental tapestry that makes up our inner world.